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Moitzi AM, Krššák M, Klepochova R, Triska C, Csapo R, König D. Effects of a 10-Week Exercise and Nutritional Intervention with Variable Dietary Carbohydrates and Glycaemic Indices on Substrate Metabolism, Glycogen Storage, and Endurance Performance in Men: A Randomized Controlled Trial. SPORTS MEDICINE - OPEN 2024; 10:36. [PMID: 38600291 PMCID: PMC11006643 DOI: 10.1186/s40798-024-00705-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/24/2024] [Indexed: 04/12/2024]
Abstract
BACKGROUND Daily nutrition plays an important role in supporting training adaptions and endurance performance. The objective of this 10-week study was to investigate the consequences of varying carbohydrate consumption and the glycaemic index (GI) together with an endurance training regimen on substrate oxidation, muscle energy storage and endurance performance under free-living conditions. Sixty-five moderately trained healthy men (29 ± 4 years; VO2 peak 55 ± 8 mL min-1 kg-1) were randomized to one of three different nutritional regimes (LOW-GI: 50-60% CHO with ≥ 65% of these CHO with GI < 50 per day, n = 24; HIGH-GI: 50-60% CHO with ≥ 65% CHO with GI > 70 per day, n = 20; LCHF: ≤ 50 g CHO daily, n = 21). Metabolic alterations and performance were assessed at baseline (T0) and after 10 weeks (T10) during a graded exercise treadmill test. Additionally, a 5 km time trial on a 400-m outdoor track was performed and muscle glycogen was measured by magnet resonance spectroscopy. RESULTS Total fat oxidation expressed as area under the curve (AUC) during the graded exercise test increased in LCHF (1.3 ± 2.4 g min-1 × km h-1, p < 0.001), remained unchanged in LOW-GI (p > 0.05) and decreased in HIGH-GI (- 1.7 ± 1.5 g min-1 × km h-1, p < 0.001). After the intervention, LOW-GI (- 0.4 ± 0.5 mmol L-1 × km h-1, p < 0.001) and LCHF (- 0.8 ± 0.7 mmol L-1 × km h-1, p < 0.001) showed significantly lower AUC of blood lactate concentrations. Peak running speed increased in LOW-GI (T0: 4.3 ± 0.4 vs. T10: 4.5 ± 0.3 m s-1, p < 0.001) and HIGH-GI (T0: 4.4 ± 0.5 vs. T10: 4.6 ± 0.4 m s-1), while no improvement was observed in LCHF. Yet, time trial performance improved significantly in all groups. Muscle glycogen content increased for participants in HIGH-GI (T0: 97.3 ± 18.5 vs. T10: 144.5 ± 39.8 mmol L wet-tissue-1, p = 0.027) and remained unchanged in the LOW-GI and the LCHF group. At the last examination, muscle glycogen concentration was significantly higher in LOW-GI compared to LCHF (p = 0.014). CONCLUSION Changes in fat oxidation were only present in LCHF, however, lower lactate concentrations in LOW-GI resulted in changes indicating an improved substrate metabolism. Compared to a LCHF diet, changes in peak running speed, and muscle glycogen stores were superior in LOW- and HIGH-GI diets. The low GI diet seems to have an influence on substrate metabolism without compromising performance at higher intensities, suggesting that a high-carbohydrate diet with a low GI is a viable alternative to a LCHF or a high GI diet. TRIAL REGISTRATION Clinical Trials, NCT05241730. https://clinicaltrials.gov/study/NCT05241730 . Registered 25 January 2021.
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Affiliation(s)
- Anna Maria Moitzi
- Division of Nutrition, Exercise and Health, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, Vienna, Austria.
- Division of Nurtition, Exercise and Health, Department of Sport and Human Movement Science, University of Vienna, Vienna, Austria.
| | - Martin Krššák
- Department of Biomedical Imaging and Image Guided Therapy, High Field MR Centre of Excellence, Medical University of Vienna, Vienna, Austria
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Radka Klepochova
- Department of Biomedical Imaging and Image Guided Therapy, High Field MR Centre of Excellence, Medical University of Vienna, Vienna, Austria
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Christoph Triska
- Leistungssport Austria, High Performance Centre, Brunn am Gebirge, Lower Austria, Austria
- Division of Training Science, Department of Sport and Human Movement Science, University of Vienna, Vienna, Austria
| | - Robert Csapo
- Division of Training Science, Department of Sport and Human Movement Science, University of Vienna, Vienna, Austria
| | - Daniel König
- Division of Nutrition, Exercise and Health, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- Division of Nurtition, Exercise and Health, Department of Sport and Human Movement Science, University of Vienna, Vienna, Austria
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Kruszewski M, Kruszewski A, Tabęcki R, Kuźmicki S, Stec K, Ambroży T, Aksenov MO, Merchelski M, Danielik T. Effectiveness of high-fat and high-carbohydrate diets on body composition and maximal strength after 15 weeks of resistance training. Adv Med Sci 2024; 69:139-146. [PMID: 38428587 DOI: 10.1016/j.advms.2024.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/09/2023] [Accepted: 02/25/2024] [Indexed: 03/03/2024]
Abstract
PURPOSE The aim of this study was to compare High Carbohydrates Low Fat (HCLF) and Low Carbohydrate High Fat (LCHF) diets in terms of changes in body composition and maximal strength. PATIENTS/METHODS The study involved 48 men aged 25 ± 2.5, divided into two groups, one of which (n = 23) was following the LCHF diet and the other (n = 25) the HCLF diet. Both groups performed the same resistance training protocol for 15 weeks. Maximal strength in squat, bench press and deadlift was assessed pre- and post-intervention. Measurements of selected body circumferences and tissue parameters were made using the multifunctional, multi-frequency, direct bioelectric impedance InBody 770 analyzer from InBody Co., Ltd (Cerritos, California, USA). The team with the necessary qualifications and experience in research performed all the measurements and maintained participants' oversight throughout the entire length of the study. RESULTS Both nutritional approaches were effective in terms of reducing body fat mass. The HCLF group achieved greater skeletal muscle hypertrophy. Significant decreases in body circumferences, especially in the abdominal area, were observed for both dietary approaches. Maximal strength significantly increased in the HCLF group and decreased in the LCHF group. CONCLUSION Holistic analysis of the results led to the conclusion that both dietary approaches may elicit positive adaptations in body composition. The two approaches constitute useful alternatives for both recreational exercisers and physique athletes with body composition goals.
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Affiliation(s)
- Marek Kruszewski
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland.
| | - Artur Kruszewski
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Rafał Tabęcki
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Stanisław Kuźmicki
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Krzysztof Stec
- Department of Health Sciences, Jan Długosz University in Częstochowa, Częstochowa, Poland
| | - Tadeusz Ambroży
- Institute of Sport Sciences, University of Physical Education in Kraków, Cracow, Poland
| | - Maksim Olegovich Aksenov
- Plekhanov Russian University of Economics, Academic Department of Physical Education, Moscow, Russia; Banzarov Buryat State University, Department of Physical Education Theory, Faculty of Physical Training, Sport and Tourism, Ulan-Ude, Russia
| | - Maciej Merchelski
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
| | - Tomasz Danielik
- Department of Physical Education, Józef Piłsudski University of Physical Education in Warsaw, Warsaw, Poland
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Tortadès M, Marti S, Devant M, Vidal M, Fàbregas F, Terré M. Feeding colostrum and transition milk facilitates digestive tract functionality recovery from feed restriction and fasting of dairy calves. J Dairy Sci 2023; 106:8642-8657. [PMID: 37641341 DOI: 10.3168/jds.2023-23345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/14/2023] [Indexed: 08/31/2023]
Abstract
The objective of this study was to evaluate the digestive tract recovery and metabolism of feeding either bovine colostrum (BC), transition milk (TM), or milk replacer (MR) after an episode of feed restriction and fasting (FRF) in dairy calves. Thirty-five Holstein male calves (22 ± 4.8 d old) were involved in a 50-d study. After 3 d of feeding 2 L of rehydration solution twice daily and 19 h of fasting (d 1 of study), calves were randomly assigned to one of the 5 feeding treatments (n = 7): calves were offered either pooled BC during 4 (C4) or 10 (C10) days, pooled TM during 4 (TM4) or 10 (TM10) days, or MR for 10 d (CTRL) at the rate of 720 g/d DM content. Then, all calves were fed the same feeding program, gradually decreasing MR from 3 L twice daily to 2 L once daily at 12.5% DM until weaning (d 42), and concentrate feed, water, and straw were offered ad libitum until d 50. Citrulline, Cr-EDTA, β-hydroxybutyrate (BHB), and nonesterified fatty acids (NEFA) in serum and complete blood count (CBC) were determined on d -3, 1, 2, 5, and 11 relative to FRF, except BHB and NEFA at d -3. Volatile fatty acids (VFA), lactoferrin (LTF), IgA, and microbiota (Firmicutes to Bacteroidetes ratio and Fecalis prausnitzii) were analyzed in feces on d 5 and 11 before the morning feeding. Health scores were recorded daily from d -3 to d 14 as well as d 23 and 30. Feed concentrate, MR, and straw intake were recorded daily, and body weight on d -3, 1, 2, 5, and 11 and weekly afterward. Calf performance, intake, serum Cr-EDTA, CBC, fecal LTF concentrations and microbiota parameters were similar among treatments throughout the study. Serum NEFA concentrations were greater in TM4, TM10 and C10 calves compared with the CTRL ones from d 2 to 11, and after the FRF, serum concentrations of BHB were lower in CTRL calves than in the other treatments, and on d 11, serum BHB concentrations in the long treatments (C10 and TM10) remained greater than those in the shorter ones (C4 and TM4) and CTRL. Serum citrulline concentrations were similar on d -3 and 1 in all treatments, but they were greater in C4, C10, TM4, and TM10 on d 2 and 5, and on d 11 they were only greater in C10 and TM10 than in CTRL calves. Fecal IgA concentrations tended to be greater in C10 than in CTRL, TM4, and TM10 calves, and in C4 and TM10 than in CTRL animals. Fecal propionate proportion was lesser in C10 than in CTRL, TM4, and TM10 calves, while butyrate was greater in C4 and C10 than in TM4 and CTRL calves. The proportion of non-normal fecal scores of C10 fed calves was greater than TM4 and TM10 calves. Results showed that TM and BC may help to recover intestinal functionality, provide gut immune protection, and increase liver fatty acid oxidation in calves after a FRF episode.
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Affiliation(s)
- M Tortadès
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain
| | - S Marti
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain
| | - M Devant
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain
| | - M Vidal
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain
| | - F Fàbregas
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain
| | - M Terré
- Department of Ruminant Production, IRTA (Institut de Recerca i Tecnologia Agroalimentàries), 08140 Caldes de Montbui, Barcelona, Spain.
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Moitzi AM, König D. Longer-Term Effects of the Glycaemic Index on Substrate Metabolism and Performance in Endurance Athletes. Nutrients 2023; 15:3028. [PMID: 37447354 DOI: 10.3390/nu15133028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023] Open
Abstract
Nutrition has a decisive influence on athletic performance. However, it is not only the nutrient intake during exercise that is important, but the daily diet must also be adapted to the requirements of physical activity in order to optimally promote training adaptations. The goal of prolonged endurance training is to enhance fat oxidation, to maintain aerobic performance at a higher intensity while sparing limited carbohydrate stores. The targeted modification of macronutrient intake is a common method of influencing substrate metabolism, fuel selection, and performance. However, it is not well established whether the glycaemic index of carbohydrates in our daily diet can improve endurance performance by influencing carbohydrate or fat oxidation during training. Therefore, the aim of the following review is to elucidate the possible influence of the glycaemic index on substrate utilization during exercise and to clarify whether the consumption of a long-term high-carbohydrate diet with different glycaemic indices may have an influence on substrate metabolism and endurance performance.
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Affiliation(s)
- Anna Maria Moitzi
- Division for Nutrition, Exercise and Health, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
- Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, 1090 Vienna, Austria
| | - Daniel König
- Division for Nutrition, Exercise and Health, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
- Division for Nutrition, Exercise and Health, Department of Sport Science, Centre for Sports Science and University Sports, University of Vienna, 1150 Vienna, Austria
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Chiarello N, Leger B, De Riedmatten M, Rossier MF, Vuistiner P, Duc M, Rapillard A, Allet L. Effect of a four-week isocaloric ketogenic diet on physical performance at very high-altitude: a pilot study. BMC Sports Sci Med Rehabil 2023; 15:37. [PMID: 36941621 PMCID: PMC10029223 DOI: 10.1186/s13102-023-00649-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 03/13/2023] [Indexed: 03/23/2023]
Abstract
BACKGROUND A ketogenic diet (KD) reduces daily carbohydrates (CHOs) ingestion by replacing most calories with fat. KD is of increasing interest among athletes because it may increase their maximal oxygen uptake (VO2max), the principal performance limitation at high-altitudes (1500-3500 m). We examined the tolerance of a 4-week isocaloric KD (ICKD) under simulated hypoxia and the possibility of evaluating ICKD performance benefits with a maximal graded exercise bike test under hypoxia and collected data on the effect of the diet on performance markers and arterial blood gases. METHODS In a randomised single-blind cross-over model, 6 recreational mountaineers (age 24-44 years) completed a 4-week ICKD followed or preceded by a 4-week usual mixed Western-style diet (UD). Performance parameters (VO2max, lactate threshold [LT], peak power [Ppeak]) and arterial blood gases (PaO2, PaCO2, pH, HCO3-) were measured at baseline under two conditions (normoxia and hypoxia) as well as after a 4-week UD and 4-week ICKD under the hypoxic condition. RESULTS We analysed data for all 6 participants (BMI 19.9-24.6 kg m-2). Mean VO2max in the normoxic condition was 44.6 ml kg-1 min-1. Hypoxia led to decreased performance in all participants. With the ICKD diet, median values for PaO2 decreased by - 14.5% and VO2max by + 7.3% and Ppeak by + 4.7%. CONCLUSION All participants except one could complete the ICKD. VO2max improved with the ICKD under the hypoxia condition. Therefore, an ICKD is an interesting alternative to CHOs dependency for endurance performance at high-altitudes, including high-altitude training and high-altitude races. Nevertheless, decreased PaO2 with ICKD remains a significant limitation in very-high to extreme altitudes (> 3500 m). Trial registration Clinical trial registration Nr. NCT05603689 (Clinicaltrials.gov). Ethics approval CER-VD, trial Nr. 2020-00427, registered 18.08.2020-prospectively registered.
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Affiliation(s)
- Nicolas Chiarello
- Department of Medicine, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
| | | | | | - Michel F. Rossier
- Service of Clinical Chemistry and Toxicology, Central Institute of the Hospitals – HVS, Sion, Switzerland
- Department of Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Philippe Vuistiner
- Institute for Research in Rehabilitation, Clinique romande de réadaptation, Sion, Switzerland
| | - Michael Duc
- Swiss Olympic Medical Center, Clinique romande de réadaptation, Sion, Switzerland
| | - Arnaud Rapillard
- Swiss Olympic Medical Center, Clinique romande de réadaptation, Sion, Switzerland
| | - Lara Allet
- Department of Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Valais-Wallis School of Health Sciences, HES-SO, University of Applied Sciences and Arts Western Switzerland, Valais, Switzerland
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Watanabe S, Tsujino S. Applications of Medium-Chain Triglycerides in Foods. Front Nutr 2022; 9:802805. [PMID: 35719157 PMCID: PMC9203050 DOI: 10.3389/fnut.2022.802805] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 05/06/2022] [Indexed: 11/17/2022] Open
Abstract
In the 1950s, the production of processed fats and oils from coconut oil was popular in the United States. It became necessary to find uses for the medium-chain fatty acids (MCFAs) that were byproducts of the process, and a production method for medium-chain triglycerides (MCTs) was established. At the time of this development, its use as a non-fattening fat was being studied. In the early days MCFAs included fatty acids ranging from hexanoic acid (C6:0) to dodecanoic acid (C12:0), but today their compositions vary among manufacturers and there seems to be no clear definition. MCFAs are more polar than long-chain fatty acids (LCFAs) because of their shorter chain length, and their hydrolysis and absorption properties differ greatly. These differences in physical properties have led, since the 1960s, to the use of MCTs to improve various lipid absorption disorders and malnutrition. More than half a century has passed since MCTs were first used in the medical field. It has been reported that they not only have properties as an energy source, but also have various physiological effects, such as effects on fat and protein metabolism. The enhancement of fat oxidation through ingestion of MCTs has led to interest in the study of body fat reduction and improvement of endurance during exercise. Recently, MCTs have also been shown to promote protein anabolism and inhibit catabolism, and applied research has been conducted into the prevention of frailty in the elderly. In addition, a relatively large ingestion of MCTs can be partially converted into ketone bodies, which can be used as a component of "ketone diets" in the dietary treatment of patients with intractable epilepsy, or in the nutritional support of terminally ill cancer patients. The possibility of improving cognitive function in dementia patients and mild cognitive impairment is also being studied. Obesity due to over-nutrition and lack of exercise, and frailty due to under-nutrition and aging, are major health issues in today's society. MCTs have been studied in relation to these concerns. In this paper we will introduce the results of applied research into the use of MCTs by healthy subjects.
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Cao J, Lei S, Wang X, Cheng S. The Effect of a Ketogenic Low-Carbohydrate, High-Fat Diet on Aerobic Capacity and Exercise Performance in Endurance Athletes: A Systematic Review and Meta-Analysis. Nutrients 2021; 13:2896. [PMID: 34445057 PMCID: PMC8400555 DOI: 10.3390/nu13082896] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/02/2021] [Accepted: 08/19/2021] [Indexed: 12/29/2022] Open
Abstract
A low-carbohydrate, high-fat (LCHF) diet has been proposed to enhance the fat utilization of muscle and the aerobic capacity of endurance athletes, thereby improving their exercise performance. However, it remains uncertain how the macronutrient intake shift from carbohydrate to fat affects endurance exercise training and performance. This study performed a systematic review and meta-analysis to explore the effects of a ketogenic low-carbohydrate, high-fat (K-LCHF) diet on aerobic capacity and exercise performance among endurance athletes. Searches were carried out in five electronic databases, and we followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The search included studies using an LCHF diet as an intervention protocol and compared data on factors such as maximum oxygen uptake (VO2max) and rating of perceived exertion (RPE) from the graded exercise test. In this case, 10 studies met the criteria and were included in the meta-analysis. We did not find a significant effect of K-LCHF diet interventions on VO2max, time to exhaustion, HRmax or RPE. However, a significant overall effect in the substrate oxidation response to respiratory exchange rate was observed. The meta-analysis showed that K-LCHF diets did not affect aerobic capacity and exercise performance. Therefore, high-quality interventions of a K-LCHF diet are needed to illustrate its effect on various endurance training programs.
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Affiliation(s)
- Jingguo Cao
- Exercise, Health and Technology Centre, Department of Physical Education, Shanghai Jiao Tong University, Shanghai 200240, China; (J.C.); (S.L.); (S.C.)
| | - Siman Lei
- Exercise, Health and Technology Centre, Department of Physical Education, Shanghai Jiao Tong University, Shanghai 200240, China; (J.C.); (S.L.); (S.C.)
- Faculty of Education, University of Macau, Macau SAR, China
| | - Xiuqiang Wang
- Exercise, Health and Technology Centre, Department of Physical Education, Shanghai Jiao Tong University, Shanghai 200240, China; (J.C.); (S.L.); (S.C.)
- Exercise Translational Medicine Centre, Shanghai Centre for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sulin Cheng
- Exercise, Health and Technology Centre, Department of Physical Education, Shanghai Jiao Tong University, Shanghai 200240, China; (J.C.); (S.L.); (S.C.)
- Exercise Translational Medicine Centre, Shanghai Centre for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
- Faculty of Sport and Health Science, University of Jyväskylä, 40014 Jyväskylä, Finland
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Durkalec-Michalski K, Nowaczyk PM, Główka N, Ziobrowska A, Podgórski T. Is a Four-Week Ketogenic Diet an Effective Nutritional Strategy in CrossFit-Trained Female and Male Athletes? Nutrients 2021; 13:nu13030864. [PMID: 33800770 PMCID: PMC8001376 DOI: 10.3390/nu13030864] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/27/2021] [Accepted: 03/02/2021] [Indexed: 12/12/2022] Open
Abstract
This single-arm interventional study examined the effect of a 4-week ketogenic diet (KD) on aerobic capacity and discipline-specific performance in female (n = 11) and male (n = 11) CrossFit-trained athletes. The participants performed incremental cycling (ICT) and Fight Gone Bad (FGB) tests after consuming a customary diet and a KD. Pre- and post-ICT exercise blood samples were also analysed. Consuming a KD had a slight impact on aerobic capacity and no relevant effect on CrossFit-specific performance. In females, consuming a KD led to an 10.4% decrease in peak oxygen uptake during the ICT (p = 0.027) and resulted in certain alterations in haematological parameters (haemoglobin (HGB), mean corpuscular HGB, and mean corpuscular HGB concentration). Furthermore, in males, alanine aminotransferase activity increased with a simultaneous improvement in the post-ICT blood acid–base balance after consuming a KD. The pre-exercise bilirubin concentration was also elevated in the entire group after consuming a KD. In conclusion, female CrossFit-trained athletes seem to be prone to aerobic performance decrements and increased risk of developing haematological disturbances when consuming a KD. In males who consumed a KD, there was an undesirable alanine aminotransferase elevation and a small tendency towards improved acid–base status. Moreover, consuming a KD had no effect on discipline-specific performance in CrossFit-trained athletes.
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Affiliation(s)
- Krzysztof Durkalec-Michalski
- Department of Sports Dietetics, Poznan University of Physical Education, 61-871 Poznań, Poland
- Department of Human Nutrition and Dietetics, Poznan University of Life Sciences, 60-624 Poznań, Poland; (P.M.N.); (N.G.); (A.Z.)
- Correspondence:
| | - Paulina M. Nowaczyk
- Department of Human Nutrition and Dietetics, Poznan University of Life Sciences, 60-624 Poznań, Poland; (P.M.N.); (N.G.); (A.Z.)
| | - Natalia Główka
- Department of Human Nutrition and Dietetics, Poznan University of Life Sciences, 60-624 Poznań, Poland; (P.M.N.); (N.G.); (A.Z.)
| | - Anna Ziobrowska
- Department of Human Nutrition and Dietetics, Poznan University of Life Sciences, 60-624 Poznań, Poland; (P.M.N.); (N.G.); (A.Z.)
| | - Tomasz Podgórski
- Department of Physiology and Biochemistry, Poznan University of Physical Education, 61-871 Poznań, Poland;
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Caloric restriction following early-life high fat-diet feeding represses skeletal muscle TNF in male rats. J Nutr Biochem 2021; 91:108598. [PMID: 33549890 DOI: 10.1016/j.jnutbio.2021.108598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/03/2020] [Accepted: 01/08/2021] [Indexed: 02/06/2023]
Abstract
Chronic metabolic diseases are on the rise worldwide and their etiology is multifactorial. Among them, inflammatory components like Tumor Necrosis Factor (TNF), contribute to whole-body metabolic impairment. Caloric Restriction (CR) combats metabolic diseases, but how it reduces inflammation remains understudied. We aimed to evaluate the impact of chronic CR on muscle inflammation, in particular TNF. In our study, 4-week old male Sprague-Dawley rats were fed a high-fat diet (HF, 45% Kcal of fat from lard) ad libitum for 3 months. After estimation of their energy requirement (1 month), they were then divided into three groups: HF ad libitum (OL), weight maintenance with AIN93M (9.5% Kcal from fat; ML, 100% of energy requirement), and caloric restriction (CR, AIN93M with 75% of energy requirement). This dietary intervention continued for six months. At this point, rats were sacrificed and gastrocnemius muscle was collected. CR induced a profound shift in fat and lean mass, and decreased growth factor IGF-1. Muscle qPCR analysis showed a marked decrease in inflammation and TNF (premRNA, mRNA, and protein) by CR, accompanied by Tnf promoter DNA hypermethylation. CR increased expression of histone deacetylase Sirt6 and decreased methyltransferase Suv39h1, together with decreased Tnf promoter and coding region binding of NF- κB and C/EBP-β. Following miRNA database mining, qPCR analysis revealed that CR downregulated the proinflammatory miR-19b and increased the anti-inflammatory miR-181a and its known targets. Chronic CR is able to regulate muscle-specific inflammation by targeting the NF-κB pathway as well as transcriptional and post-transcriptional regulation of Tnf gene.
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Kaviani M, Izadi A, Heshmati J. Would creatine supplementation augment exercise performance during a low carbohydrate high fat diet? Med Hypotheses 2020; 146:110369. [PMID: 33214000 DOI: 10.1016/j.mehy.2020.110369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 10/06/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023]
Abstract
Low carbohydrate high fat (LCHF) diets are emerging in popularity. Several athletics have adopted LCHF diets in an attempt to improve exercise performance and body composition by enhancing fat utilization. However, these diets impair maximal and supramaximal exercise performance due to limited glycogen stores as well as increasing ratings of perceived exertion (RPE). All of these factors may impact training volume and compliance, leading to less optimal training adaptations over time. In contrast, LCHF diets is an effective strategy for weight and fat mass loss and is beneficial for a variety of metabolic processes. One potential nutritional strategy to off-set the negative aspects of a LCHF is creatine (Cr). Creatine supplementation has been shown to increase muscle power output and reduce the rate of fatigue; thereby allowing individuals to work at a higher intensity for a greater duration. Furthermore, Cr supplementation may positively enhance body composition (gains in muscle mass and possibly aid in fat mass loss). Despite the popularity of both LCHF and creatine supplementation, there is no data available investigating the effects of Cr supplementation on exercise performance and body composition during LCHF diets in humans. We would hypothesize that Cr supplementation may augment exercise performance (anerobic power and strength) during a LCHF diet compared to a LCHF diet and placebo. In addition, combining Cr with a LCHF diet would further increase body fat loss and improve body composition compared to a LCHF diet and/or low-fat diets (LFDs) placebo. Our hypotheses would be under the assumption that total caloric intake and protein intake are matched. Future research is warranted to examine chronic exercise with LCHF diets with and without creatine and compare performance and body composition changes to high carbohydrate diets.
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Affiliation(s)
- Mojtaba Kaviani
- School of Nutrition and Dietetics, Faculty of Pure and Applied Science, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada.
| | - Azimeh Izadi
- Department of Biochemistry and Diet Therapy, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Javad Heshmati
- Department of Nutritional Science, School of Nutritional Science and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Prevalence and Determinants of Fasted Training in Endurance Athletes: A Survey Analysis. Int J Sport Nutr Exerc Metab 2020; 30:345-356. [DOI: 10.1123/ijsnem.2020-0109] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 11/18/2022]
Abstract
Athletes may choose to perform exercise in the overnight-fasted state for a variety of reasons related to convenience, gut comfort, or augmenting the training response, but it is unclear how many endurance athletes use this strategy. We investigated the prevalence and determinants of exercise performed in the overnight-fasted state among endurance athletes using an online survey and examined differences based on sex, competitive level, and habitual dietary pattern. The survey was completed by 1,950 endurance athletes (51.0% female, mean age 40.9 ± 11.1 years). The use of fasted training was reported by 62.9% of athletes, with significant effects of sex (p < .001, Cramer’s V [φc] = 0.18, 90% CI [0.14, 0.22]), competitive level (p < .001, φc = 0.09, 90% CI [0.5, 0.13]), and habitual dietary pattern noted (p < .001, φc = 0.26, 90% CI [0.22, 0.29]). Males, nonprofessional athletes, and athletes following a low-carbohydrate, high-fat diet were most likely to perform fasted training. The most common reasons for doing so were related to utilizing fat as a fuel source (42.9%), gut comfort (35.5%), and time constraints/convenience (31.4%), whereas the most common reasons athletes avoided fasted training were that it does not help their training (47.0%), performance was worse during fasted training (34.7%), or greater hunger (34.6%). Overall, some athletes perform fasted training because they think it helps their training, whereas others avoid it because they think it is detrimental to their training goals, highlighting a need for future research. These findings offer insights into the beliefs and practices related to fasted-state endurance training.
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Shaw DM, Merien F, Braakhuis A, Maunder ED, Dulson DK. Effect of a Ketogenic Diet on Submaximal Exercise Capacity and Efficiency in Runners. Med Sci Sports Exerc 2020; 51:2135-2146. [PMID: 31033901 DOI: 10.1249/mss.0000000000002008] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE We investigated the effect of a 31-d ketogenic diet (KD) on submaximal exercise capacity and efficiency. METHODS A randomized, repeated-measures, crossover study was conducted in eight trained male endurance athletes (V˙O2max, 59.4 ± 5.2 mL⋅kg⋅min). Participants ingested their habitual diet (HD) (13.1 MJ, 43% [4.6 g⋅kg⋅d] carbohydrate and 38% [1.8 g⋅kg⋅d] fat) or an isoenergetic KD (13.7 MJ, 4% [0.5 g·kg⋅d] carbohydrate and 78% [4 g⋅kg⋅d] fat) from days 0 to 31 (P < 0.001). Participants performed a fasted metabolic test on days -2 and 29 (~25 min) and a run-to-exhaustion trial at 70% V˙O2max on days 0 and 31 following the ingestion of a high-carbohydrate meal (2 g⋅kg) or an isoenergetic low-carbohydrate, high-fat meal (<10 g CHO), with carbohydrate (~55 g⋅h) or isoenergetic fat (0 g CHO⋅h) supplementation during exercise. RESULTS Training loads were similar between trials and V˙O2max was unchanged (all, P > 0.05). The KD impaired exercise efficiency, particularly at >70% V˙O2max, as evidenced by increased energy expenditure and oxygen uptake that could not be explained by shifts in respiratory exchange ratio (RER) (all, P < 0.05). However, exercise efficiency was maintained on a KD when exercising at <60% V˙O2max (all, P > 0.05). Time-to-exhaustion (TTE) was similar for each dietary adaptation (pre-HD, 237 ± 44 vs post-HD, 231 ± 35 min; P = 0.44 and pre-KD, 239 ± 27 vs post-KD, 219 ± 53 min; P = 0.36). Following keto-adaptation, RER >1.0 vs <1.0 at V˙O2max coincided with the preservation and reduction in TTE, respectively. CONCLUSION A 31-d KD preserved mean submaximal exercise capacity in trained endurance athletes without necessitating acute carbohydrate fuelling strategies. However, there was a greater risk of an endurance decrement at an individual level.
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Affiliation(s)
- David M Shaw
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, NEW ZEALAND
| | - Fabrice Merien
- AUT-Roche Diagnostics Laboratory, School of Science, Auckland University of Technology, Auckland, NEW ZEALAND
| | - Andrea Braakhuis
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, NEW ZEALAND
| | - E D Maunder
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, NEW ZEALAND
| | - Deborah K Dulson
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, NEW ZEALAND
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13
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Bigard X. Les corps cétoniques et les performances en endurance. Qu’en penser en 2019 ? Sci Sports 2019. [DOI: 10.1016/j.scispo.2019.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Dostal T, Plews DJ, Hofmann P, Laursen PB, Cipryan L. Effects of a 12-Week Very-Low Carbohydrate High-Fat Diet on Maximal Aerobic Capacity, High-Intensity Intermittent Exercise, and Cardiac Autonomic Regulation: Non-randomized Parallel-Group Study. Front Physiol 2019; 10:912. [PMID: 31379612 PMCID: PMC6652046 DOI: 10.3389/fphys.2019.00912] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/03/2019] [Indexed: 11/13/2022] Open
Abstract
Purpose The aim of this non-randomized parallel group study was to examine the 12 week effects of a very low-carbohydrate high-fat diet (VLCHF) on maximal cardiorespiratory capacity, high-intensity interval training (HIIT) performance, and cardiac autonomic regulation. Methods Twenty-four recreationally trained participants allocated to either a VLCHF (N = 12) or a habitual diet (HD; N = 12) group completed 12 weeks of a diet and exercise (VLCHF) or an exercise only intervention (HD). Maximal graded exercise tests (GXT) were performed at baseline, after 4, 8, and 12 weeks. A supervised HIIT session and the 30-15 Intermittent Fitness Test (30-15IFT) were conducted once a week. Results Total time to exhaustion (TTE) in both GXT and 30-15IFTlargely increased in both VLCHF (p = 0.005, BF10 = 11.30 and p = 0.001, BF10 ≥ 100, respectively) and HD (p = 0.018, BF10 = 3.87 and p = 0.001, BF10 ≥ 100, respectively) groups after 12 weeks. Absolute maximal oxygen uptake (V˙O2max) was not changed in both groups but relative V˙O2max increased in VLCHF in concert with reductions in body mass (66.7 ± 10.2–63.1 ± 8.5 kg). Cardiac autonomic regulation did not reveal any between-group differences after 12 weeks. VLCHF diet induced an increase in β-hydroxybutyrate, which tended to normalize during the intervention period. Conclusion The 12 week VLCHF diet did not impair high-intensity continuous or intermittent exercise lasting up to 25 min, nor did it impair maximal cardiorespiratory performance or autonomic nervous system (ANS) activity.
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Affiliation(s)
- Tomas Dostal
- Department of Human Movement Studies, Human Motion Diagnostic Centre, University of Ostrava, Ostrava, Czechia
| | - Daniel J Plews
- Sport Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand
| | - Peter Hofmann
- Exercise Physiology, Training and Training Therapy Research Group, Institute of Sports Science, University of Graz, Graz, Austria
| | - Paul B Laursen
- Sport Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand
| | - Lukas Cipryan
- Department of Human Movement Studies, Human Motion Diagnostic Centre, University of Ostrava, Ostrava, Czechia
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Allman BR, Morrissey MC, Kim JS, Panton LB, Contreras RJ, Hickner RC, Ormsbee MJ. Fat metabolism and acute resistance exercise in trained women. J Appl Physiol (1985) 2019; 126:739-745. [PMID: 30605402 DOI: 10.1152/japplphysiol.00752.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated the effect of acute full-body resistance exercise [RE; one set of 10 repetitions at 40% 1 repetition maximum (1RM) and three sets of 10 repetitions at 65% 1RM] on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole body substrate oxidation in young (age: 22 ± 1 yr), normal-weight and body fatness (body mass index: 20 ± 1 kg/m2; %body fat: 28.7 ± 1.4%), resistance-trained women. Microdialysis was used to measure SCAAT lipolysis at baseline, mid-RE, post-RE, and 30 min post-RE, and indirect calorimetry was used to measure whole body substrate oxidation at baseline and immediately post-RE in 13 women. Plasma concentrations of glucose, insulin, nonesterified fatty acids (NEFA), glycerol, growth hormone (GH), epinephrine (Epi), and norepinephrine (NE) were measured at baseline, mid-RE, and post-RE. Lipolysis (dialysate glycerol concentration) was elevated post-RE (baseline: 596.7 ± 82.8, post-RE: 961.4 ± 116.3 µM, P = 0.01). Energy expenditure (baseline: 1,560 ± 49; post-RE: 1,756 ± 68 kcal/day; P = 0.02) and fat oxidation (baseline: 5.64 ± 0.24; post-RE: 7.57 ± 0.41 g/h; P = 0.0003) were elevated post-RE. GH (baseline: 513.1 ± 147.4; mid-RE: 1,288.3 ± 83.9; post-RE: 1,522.8 ± 51.1 pg/ml, P = 0.000), Epi (baseline: 23.2 ± 2.7; mid-RE: 92.5 ± 16.6; post-RE: 84.5 ± 21.4 pg/ml, P = 0.000), and NE (baseline: 139.2 ± 13.6; mid-RE: 850.9 ± 155.3; post-RE: 695.3 ± 93.5 pg/ml, P = 0.000) were higher at mid-RE and post-RE. Therefore, one of the potential mechanisms behind RE-induced fat mass changes in resistance-trained women may be in part due to the accumulated effect of transient increases in SCAAT lipolysis, fat oxidation, and energy expenditure, mediated by GH, Epi, and NE release.
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Affiliation(s)
- Brittany R Allman
- Department of Nutrition, Food, and Exercise Sciences, Institute of Sports Sciences & Medicine, Florida State University , Tallahassee, Florida
| | - Margaret C Morrissey
- Department of Kinesiology, Korey Stringer Institute, University of Connecticut , Storrs, Connecticut
| | - Jeong-Su Kim
- Department of Nutrition, Food, and Exercise Sciences, Institute of Sports Sciences & Medicine, Florida State University , Tallahassee, Florida
- Department of Nutrition, Food, and Exercise Sciences, Institute of Successful Longevity, Florida State University , Tallahassee, Florida
| | - Lynn B Panton
- Department of Nutrition, Food, and Exercise Sciences, Institute of Sports Sciences & Medicine, Florida State University , Tallahassee, Florida
- Department of Nutrition, Food, and Exercise Sciences, Institute of Successful Longevity, Florida State University , Tallahassee, Florida
| | - Robert J Contreras
- Department of Psychology, Florida State University , Tallahassee, Florida
| | - Robert C Hickner
- Department of Nutrition, Food, and Exercise Sciences, Institute of Sports Sciences & Medicine, Florida State University , Tallahassee, Florida
- Department of Nutrition, Food, and Exercise Sciences, Institute of Successful Longevity, Florida State University , Tallahassee, Florida
- Discipline of Biokinetics, Exercise, and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Michael J Ormsbee
- Department of Nutrition, Food, and Exercise Sciences, Institute of Sports Sciences & Medicine, Florida State University , Tallahassee, Florida
- Department of Nutrition, Food, and Exercise Sciences, Institute of Successful Longevity, Florida State University , Tallahassee, Florida
- Discipline of Biokinetics, Exercise, and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
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Three-Year Chronic Consumption of Low-Carbohydrate Diet Impairs Exercise Performance and Has a Small Unfavorable Effect on Lipid Profile in Middle-Aged Men. Nutrients 2018; 10:nu10121914. [PMID: 30518095 PMCID: PMC6317154 DOI: 10.3390/nu10121914] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/24/2018] [Accepted: 11/27/2018] [Indexed: 12/17/2022] Open
Abstract
The objective of this research was to determine whether chronic (average 3.58 ± 1.56 years) deliberate adherence to low carbohydrate diets (LCDs) is associated with selected markers of metabolism, risk factors of cardiovascular disease (CVD), body mass and physical performance in apparently healthy middle-aged men (n = 12). The control group comprised age, body mass and height matched men using mixed diets (MDs). The diets used were registered for 7 days and analyzed in terms of the energy, carbohydrate, fat and protein contents. It was found that the diets used were isoenergetic, yet varied considerably in carbohydrate and fat content. The LCDs significantly intensified the ketogenesis process, increased resting blood total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and heart rate, (HR) and decreased respiratory exchange ratio (RER) in relation to MD subjects. An exercise trial revealed significant impairment of exercise in subjects following the LCDs. The results showed that in the case where the subjects of two investigated groups did not differ in their somatic variables, long-term adherence to the LCDs was associated with substantially reduced exercise performance in apparently healthy subjects, along with an association with a small unfavorable effect on their lipid profile.
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Rothschild J, Earnest CP. Dietary Manipulations Concurrent to Endurance Training. J Funct Morphol Kinesiol 2018; 3:jfmk3030041. [PMID: 33466970 PMCID: PMC7739303 DOI: 10.3390/jfmk3030041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 07/11/2018] [Accepted: 07/23/2018] [Indexed: 12/20/2022] Open
Abstract
The role of an athlete's dietary intake (both timing and food type) goes beyond simply providing fuel to support the body's vital processes. Nutritional choices also have an impact on the metabolic adaptations to training. Over the past 20 years, research has suggested that strategically reducing carbohydrate (CHO) availability during an athlete's training can modify the metabolic responses in lieu of simply maintaining a high CHO diet. Several methods have been explored to manipulate CHO availability and include: Low-carb, high-fat (LCHF) diets, performing two-a-day training without glycogen restoration between sessions, and a "sleep-low" approach entailing a glycogen-depleting session in the evening without consuming CHO until after a morning training session performed in an overnight fasted state. Each of these methods can confer beneficial metabolic adaptations for the endurance athlete including increases in mitochondrial enzyme activity, mitochondrial content, and rates of fat oxidation, yet data showing a direct performance benefit is still unclear.
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Affiliation(s)
| | - Conrad P. Earnest
- Exercise and Sport Nutrition Laboratory, Texas A&M University, College Station, TX 77843, USA
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18
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Abstract
Elite athletes and coaches are in a constant search for training methods and nutritional strategies to support training and recovery efforts that may ultimately maximize athletes’ performance. Recently, there has been a re-emerging interest in the role of ketone bodies in exercise metabolism, with considerable media speculation about ketone body supplements being routinely used by professional cyclists. Ketone bodies can serve as an important energy substrate under certain conditions, such as starvation, and can modulate carbohydrate and lipid metabolism. Dietary strategies to increase endogenous ketone body availability (i.e., a ketogenic diet) require a diet high in lipids and low in carbohydrates for ~4 days to induce nutritional ketosis. However, a high fat, low carbohydrate ketogenic diet may impair exercise performance via reducing the capacity to utilize carbohydrate, which forms a key fuel source for skeletal muscle during intense endurance-type exercise. Recently, ketone body supplements (ketone salts and esters) have emerged and may be used to rapidly increase ketone body availability, without the need to first adapt to a ketogenic diet. However, the extent to which ketone bodies regulate skeletal muscle bioenergetics and substrate metabolism during prolonged endurance-type exercise of varying intensity and duration remains unknown. Therefore, at present there are no data available to suggest that ingestion of ketone bodies during exercise improves athletes’ performance under conditions where evidence-based nutritional strategies are applied appropriately.
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Aragon AA, Schoenfeld BJ, Wildman R, Kleiner S, VanDusseldorp T, Taylor L, Earnest CP, Arciero PJ, Wilborn C, Kalman DS, Stout JR, Willoughby DS, Campbell B, Arent SM, Bannock L, Smith-Ryan AE, Antonio J. International society of sports nutrition position stand: diets and body composition. J Int Soc Sports Nutr 2017. [PMID: 28630601 PMCID: PMC5470183 DOI: 10.1186/s12970-017-0174-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of diet types (macronutrient composition; eating styles) and their influence on body composition. The ISSN has concluded the following. 1) There is a multitude of diet types and eating styles, whereby numerous subtypes fall under each major dietary archetype. 2) All body composition assessment methods have strengths and limitations. 3) Diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit may be imposed. Slower rates of weight loss can better preserve lean mass (LM) in leaner subjects. 4) Diets focused primarily on accruing LM are driven by a sustained caloric surplus to facilitate anabolic processes and support increasing resistance-training demands. The composition and magnitude of the surplus, as well as training status of the subjects can influence the nature of the gains. 5) A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition. 6) Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may result in improved body composition. Higher protein intakes (2.3–3.1 g/kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects under hypocaloric conditions. Emerging research on very high protein intakes (>3 g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects. 7) The collective body of intermittent caloric restriction research demonstrates no significant advantage over daily caloric restriction for improving body composition. 8) The long-term success of a diet depends upon compliance and suppression or circumvention of mitigating factors such as adaptive thermogenesis. 9) There is a paucity of research on women and older populations, as well as a wide range of untapped permutations of feeding frequency and macronutrient distribution at various energetic balances combined with training. Behavioral and lifestyle modification strategies are still poorly researched areas of weight management.
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Affiliation(s)
- Alan A Aragon
- Department of Family and Consumer Sciences, California State University, Northridge, CA USA
| | | | | | | | - Trisha VanDusseldorp
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA USA
| | - Lem Taylor
- Department of Exercise and Sports Science, University of Mary Hardin-Baylor, Belton, TX USA
| | - Conrad P Earnest
- Exercise and Sports Nutrition Laboratory, Texas A&M University, College Station, TX USA
| | - Paul J Arciero
- Health and Exercise Science, Skidmore College, Saratoga Springs, NY USA
| | - Colin Wilborn
- Department of Exercise and Sports Science, University of Mary Hardin-Baylor, Belton, TX USA
| | | | - Jeffrey R Stout
- Institute of Exercise Physiology and Wellness, University of Central Florida, Orlando, FL USA
| | - Darryn S Willoughby
- Department of Health, Human Performance and Recreation, Baylor University, Waco, TX USA
| | - Bill Campbell
- Performance & Physique Enhancement Laboratory, Exercise Science Program, University of South Florida, Tampa, FL USA
| | - Shawn M Arent
- Department of Kinesiology & Health, IFNH Center for Health & Human Performance, Rutgers University, New Brunswick, NJ USA
| | | | - Abbie E Smith-Ryan
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC USA
| | - Jose Antonio
- Department of Health and Human Performance, Nova Southeastern University, Davie, FL USA
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Croci I, Byrne NM, Chachay VS, Hills AP, Clouston AD, O’Moore-Sullivan TM, Prins JB, Macdonald GA, Hickman IJ. Independent effects of diet and exercise training on fat oxidation in non-alcoholic fatty liver disease. World J Hepatol 2016; 8:1137-1148. [PMID: 27721919 PMCID: PMC5037327 DOI: 10.4254/wjh.v8.i27.1137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 07/13/2016] [Accepted: 08/18/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on whole-body and hepatic fat oxidation of patients with non-alcoholic fatty liver disease (NAFLD).
METHODS Participants were randomised into either circuit exercise training (EX; n = 13; 3 h/wk without changes in dietary habits), or dietary energy restriction (ER) without changes in structured physical activity (ER; n = 8). Respiratory quotient (RQ) and whole-body fat oxidation rates (Fatox) were determined by indirect calorimetry under basal, insulin-stimulated and exercise conditions. Severity of disease and steatosis was determined by liver histology; hepatic Fatox was estimated from plasma β-hydroxybutyrate concentrations; cardiorespiratory fitness was expressed as VO2peak. Complete-case analysis was performed (EX: n = 10; ER: n = 6).
RESULTS Hepatic steatosis and NAFLD activity score decreased with ER but not with EX. β-hydroxybutyrate concentrations increased significantly in response to ER (0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L, P = 0.03) but remained unchanged in response to EX (0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L, P = 0.39). Basal RQ decreased (P = 0.05) in response to EX, while this change was not significant after ER (P = 0.38). VO2peak (P < 0.001) and maximal Fatox during aerobic exercise (P = 0.03) improved with EX but not with ER (P > 0.05). The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis (r = -0.56, P = 0.04).
CONCLUSION ER and EX lead to specific benefits on fat metabolism of patients with NAFLD. Increased hepatic Fatox in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.
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Performance Enhancing Diets and the PRISE Protocol to Optimize Athletic Performance. J Nutr Metab 2015; 2015:715859. [PMID: 25949823 PMCID: PMC4408745 DOI: 10.1155/2015/715859] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/03/2015] [Indexed: 12/14/2022] Open
Abstract
The training regimens of modern-day athletes have evolved from the sole emphasis on a single fitness component (e.g., endurance athlete or resistance/strength athlete) to an integrative, multimode approach encompassing all four of the major fitness components: resistance (R), interval sprints (I), stretching (S), and endurance (E) training. Athletes rarely, if ever, focus their training on only one mode of exercise but instead routinely engage in a multimode training program. In addition, timed-daily protein (P) intake has become a hallmark for all athletes. Recent studies, including from our laboratory, have validated the effectiveness of this multimode paradigm (RISE) and protein-feeding regimen, which we have collectively termed PRISE. Unfortunately, sports nutrition recommendations and guidelines have lagged behind the PRISE integrative nutrition and training model and therefore limit an athletes' ability to succeed. Thus, it is the purpose of this review to provide a clearly defined roadmap linking specific performance enhancing diets (PEDs) with each PRISE component to facilitate optimal nourishment and ultimately optimal athletic performance.
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Zajac A, Poprzecki S, Maszczyk A, Czuba M, Michalczyk M, Zydek G. The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists. Nutrients 2014; 6:2493-508. [PMID: 24979615 PMCID: PMC4113752 DOI: 10.3390/nu6072493] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 06/08/2014] [Accepted: 06/09/2014] [Indexed: 11/20/2022] Open
Abstract
The main objective of this research was to determine the effects of a long-term ketogenic diet, rich in polyunsaturated fatty acids, on aerobic performance and exercise metabolism in off-road cyclists. Additionally, the effects of this diet on body mass and body composition were evaluated, as well as those that occurred in the lipid and lipoprotein profiles due to the dietary intervention. The research material included eight male subjects, aged 28.3 ± 3.9 years, with at least five years of training experience that competed in off-road cycling. Each cyclist performed a continuous exercise protocol on a cycloergometer with varied intensity, after a mixed and ketogenic diet in a crossover design. The ketogenic diet stimulated favorable changes in body mass and body composition, as well as in the lipid and lipoprotein profiles. Important findings of the present study include a significant increase in the relative values of maximal oxygen uptake (VO2max) and oxygen uptake at lactate threshold (VO2 LT) after the ketogenic diet, which can be explained by reductions in body mass and fat mass and/or the greater oxygen uptake necessary to obtain the same energy yield as on a mixed diet, due to increased fat oxidation or by enhanced sympathetic activation. The max work load and the work load at lactate threshold were significantly higher after the mixed diet. The values of the respiratory exchange ratio (RER) were significantly lower at rest and during particular stages of the exercise protocol following the ketogenic diet. The heart rate (HR) and oxygen uptake were significantly higher at rest and during the first three stages of exercise after the ketogenic diet, while the reverse was true during the last stage of the exercise protocol conducted with maximal intensity. Creatine kinase (CK) and lactate dehydrogenase (LDH) activity were significantly lower at rest and during particular stages of the 105-min exercise protocol following the low carbohydrate ketogenic diet. The alterations in insulin and cortisol concentrations due to the dietary intervention confirm the concept that the glucostatic mechanism controls the hormonal and metabolic responses to exercise.
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Affiliation(s)
- Adam Zajac
- Department of Sports Training-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
| | - Stanisław Poprzecki
- Department of Biochemistry-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
| | - Adam Maszczyk
- Department of Sports Training-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
| | - Miłosz Czuba
- Department of Sports Training-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
| | - Małgorzata Michalczyk
- Department of Sports Nutrition-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
| | - Grzegorz Zydek
- Department of Sports Nutrition-Academy of Physical Education im. J. Kukuczki in Katowice, Mikolowska 72a, 40-065 Katowice, Poland.
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Aerobic exercise and not a diet supplemented with jussara açaí (Euterpe edulis Martius) alters hepatic oxidative and inflammatory biomarkers in ApoE-deficient mice. Br J Nutr 2014; 112:285-94. [PMID: 24787366 DOI: 10.1017/s000711451400083x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The pulp of jussara açaí (Euterpe edulis Martius) fruit is rich in anthocyanins that exert antioxidant and anti-inflammatory effects similar to those exerted by aerobic exercise. In the present study, we investigated the effects of jussara açaí fruit pulp consumption, either alone or in combination with aerobic exercise, on the hepatic oxidative and inflammatory status of ApoE-deficient (ApoE - / - ) mice. Male mice were divided into four groups (control (C), control plus açaí, exercise plus açaí (EXA) and exercise (EX)) and fed the AIN-93M diet or the AIN-93M diet formulated to contain 2 % freeze-dried açaí pulp. Mice in the EX and EXA groups were subjected to a progressive running programme (5 d/week, 60 min/d, 16 m/min) for 12 weeks. Mice that were made to exercise exhibited reduced (40·85 %; P< 0·05) hepatic superoxide dismutase activity when compared with the C mice, independent of the açaí diet. Mice in the EX group exhibited a lower (42 %; P< 0·05) mRNA expression of monocyte chemotactic protein-1 in the liver compared with the C mice. Mice in the EXA and EX groups had lower percentages of hepatic lipid droplets (70 % and 56 %, respectively; P< 0·05) when compared with the C mice. Mice in the EX group had smaller (58 %; P< 0·05) area of lesions in the aorta when compared with the C mice. Serum lipid profile was not affected (P>0·05). In conclusion, aerobic exercise training rather than açaí fruit pulp consumption or a combination of both enhances the hepatic oxidative and inflammatory status of ApoE - / - mice.
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Sato S, Ogura Y, Mishra V, Shin J, Bhatnagar S, Hill BG, Kumar A. TWEAK promotes exercise intolerance by decreasing skeletal muscle oxidative phosphorylation capacity. Skelet Muscle 2013; 3:18. [PMID: 23835416 PMCID: PMC3711790 DOI: 10.1186/2044-5040-3-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/09/2013] [Indexed: 11/24/2022] Open
Abstract
Background Proinflammatory cytokine tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 are the major regulators of skeletal muscle mass in many catabolic conditions. However, their role in muscle metabolism remains largely unknown. In the present study, we investigated the role of TWEAK on exercise capacity and skeletal muscle mitochondrial content and oxidative metabolism. Methods We employed wild-type and TWEAK-knockout (KO) mice and primary myotube cultures and performed biochemical, bioenergetics, and morphometric assays to evaluate the effects of TWEAK on exercise tolerance and muscle mitochondrial function and angiogenesis. Results TWEAK-KO mice showed improved exercise tolerance compared to wild-type mice. Electron microscopy analysis showed that the abundance of subsarcolemmal and intermyofibrillar mitochondria is significantly increased in skeletal muscle of TWEAK-KO mice compared to wild-type mice. Furthermore, age-related loss in skeletal muscle oxidative capacity was rescued in TWEAK-KO mice. Expression of a key transcriptional regulator peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and several other molecules involved in oxidative metabolism were significantly higher in skeletal muscle of TWEAK-KO mice. Moreover, treatment of primary myotubes with soluble TWEAK inhibited the expression of PGC-1α and mitochondrial genes and decreased mitochondrial respiratory capacity. Deletion of TWEAK also improved angiogenesis and transcript levels of vascular endothelial growth factor in skeletal muscle of mice. Conclusions These results demonstrate that TWEAK decreases mitochondrial content and oxidative phosphorylation and inhibits angiogenesis in skeletal muscle. Neutralization of TWEAK is a potential approach for improving exercise capacity and oxidative metabolism in skeletal muscle.
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Affiliation(s)
- Shuichi Sato
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, 500 South Preston Street, Louisville, KY 40202, USA.
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Décombaz J, Grathwohl D, Pollien P, Schmitt JAJ, Borrani F, Lecoultre V. Effect of short-duration lipid supplementation on fat oxidation during exercise and cycling performance. Appl Physiol Nutr Metab 2013; 38:766-72. [PMID: 23980735 DOI: 10.1139/apnm-2012-0459] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of intramyocellular lipids (IMCLs) on endurance performance with high skeletal muscle glycogen availability remains unclear. Previous work has shown that a lipid-supplemented high-carbohydrate (CHO) diet increases IMCLs while permitting normal glycogen loading. The aim of this study was to assess the effect of fat supplementation on fat oxidation (Fox) and endurance performance. Twenty-two trained male cyclists performed 2 simulated time trials (TT) in a randomized crossover design. Subjects cycled at ∼53% maximal voluntary external power for 2 h and then followed 1 of 2 diets for 2.5 days: a high-CHO low-fat (HC) diet, consisting of CHO 7.4 g·kg(-1)·day(-1) and fat 0.5 g·kg(-1)·day(-1); or a high-CHO fat-supplemented (HCF) diet, which was a replication of the HC diet with ∼240 g surplus fat (30% saturation) distributed over the last 4 meals of the diet period. On trial morning, fasting blood was sampled and Fox was measured during an incremental exercise; a ∼1-h TT followed. Breath volatile compounds (VOCs) were measured at 3 time points. Mental fatigue, measured as reaction time, was evaluated during the TT. Plasma free fatty acid concentration was 50% lower after the HCF diet (p < 0.0001), and breath acetone was reduced (p < 0.05) "at rest". Fox peaked (∼0.35 g·kg(-1)) at ∼42% peak oxygen consumption, and was not influenced by diet. Performance was not significantly different between the HCF and HC diets (3369 ± 46 s vs 3398 ± 48 s; p = 0.39), nor were reaction times to the attention task and VOCs (p = NS for both). In conclusion, the short-term intake of a lipid supplement in combination with a glycogen-loading diet designed to boost intramyocellular lipids while avoiding fat adaptation did not alter substrate oxidation during exercise or 1-hour cycling performance.
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Affiliation(s)
- Jacques Décombaz
- Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland.
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26
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Low-level laser therapy (LLLT) combined with swimming training improved the lipid profile in rats fed with high-fat diet. Lasers Med Sci 2012; 28:1271-80. [PMID: 23151893 DOI: 10.1007/s10103-012-1223-z] [Citation(s) in RCA: 258] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
Obesity and associated dyslipidemia is the fastest growing health problem throughout the world. The combination of exercise and low-level laser therapy (LLLT) could be a new approach to the treatment of obesity and associated disease. In this work, the effects of LLLT associated with exercises on the lipid metabolism in regular and high-fat diet rats were verified. We used 64 rats divided in eight groups with eight rats each, designed: SC, sedentary chow diet; SCL, sedentary chow diet laser, TC, trained chow diet; TCL, trained chow diet laser; SH, sedentary high-fat diet; SHL, sedentary high-fat diet laser; TH, trained high-fat diet; and THL, trained high-fat diet laser. The exercise used was swimming during 8 weeks/90 min daily and LLLT (GA-Al-As, 830 nm) dose of 4.7 J/point and total energy 9.4 J per animal, applied to both gastrocnemius muscles after exercise. We analyzed biochemical parameters, percentage of fat, hepatic and muscular glycogen and relative mass of tissue, and weight percentage gain. The statistical test used was ANOVA, with post hoc Tukey-Kramer for multiple analysis between groups, and the significant level was p < 0.001, p < 0.01, and p < 0.05. LLLT decreased the total cholesterol (p < 0.05), triglycerides (p < 0.01), low-density lipoprotein cholesterol (p < 0.05), and relative mass of fat tissue (p < 0.05), suggesting increased metabolic activity and altered lipid pathways. The combination of exercise and LLLT increased the benefits of exercise alone. However, LLLT without exercise tended to increase body weight and fat content. LLLT may be a valuable addition to a regimen of diet and exercise for weight reduction and dyslipidemic control.
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Constantin-Teodosiu D, Constantin D, Stephens F, Laithwaite D, Greenhaff PL. The role of FOXO and PPAR transcription factors in diet-mediated inhibition of PDC activation and carbohydrate oxidation during exercise in humans and the role of pharmacological activation of PDC in overriding these changes. Diabetes 2012; 61:1017-24. [PMID: 22315317 PMCID: PMC3331777 DOI: 10.2337/db11-0799] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
High-fat feeding inhibits pyruvate dehydrogenase complex (PDC)-controlled carbohydrate (CHO) oxidation, which contributes to muscle insulin resistance. We aimed to reveal molecular changes underpinning this process in resting and exercising humans. We also tested whether pharmacological activation of PDC overrides these diet-induced changes. Healthy males consumed a control diet (CD) and on two further occasions an isocaloric high-fat diet (HFD). After each diet, subjects cycled for 60 min after intravenous infusion with saline (CD and HFD) or dichloroacetate (HFD+DCA). Quadriceps muscle biopsies obtained before and after 10 and 60 min of exercise were used to estimate CHO use, PDC activation, and mRNAs associated with insulin, fat, and CHO signaling. Compared with CD, HFD increased resting pyruvate dehydrogenase kinase 2 (PDK2), PDK4, forkhead box class O transcription factor 1 (FOXO1), and peroxisome proliferator-activated receptor transcription factor α (PPARα) mRNA and reduced PDC activation. Exercise increased PDC activation and whole-body CHO use in HFD, but to a lower extent than in CD. Meanwhile PDK4 and FOXO1, but not PPARα or PDK2, mRNA remained elevated. HFD+DCA activated PDC throughout and restored whole-body CHO use during exercise. FOXO1 appears to play a role in HFD-mediated muscle PDK4 upregulation and inhibition of PDC and CHO oxidation in humans. Also, pharmacological activation of PDC restores HFD-mediated inhibition of CHO oxidation during exercise.
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Haramizu S, Shimotoyodome A, Fukuoka D, Murase T, Hase T. Hydroxypropylated distarch phosphate versus unmodified tapioca starch: fat oxidation and endurance in C57BL/6J mice. Eur J Appl Physiol 2012; 112:3409-16. [DOI: 10.1007/s00421-011-2301-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 12/21/2011] [Indexed: 10/14/2022]
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Helge JW, Tobin L, Drachmann T, Hellgren LI, Dela F, Galbo H. Muscle ceramide content is similar after 3 weeks’ consumption of fat or carbohydrate diet in a crossover design in patients with type 2 diabetes. Eur J Appl Physiol 2011; 112:911-8. [DOI: 10.1007/s00421-011-2041-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 06/03/2011] [Indexed: 12/25/2022]
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30
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Burke LM, Hawley JA, Wong SHS, Jeukendrup AE. Carbohydrates for training and competition. J Sports Sci 2011; 29 Suppl 1:S17-27. [PMID: 21660838 DOI: 10.1080/02640414.2011.585473] [Citation(s) in RCA: 464] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An athlete's carbohydrate intake can be judged by whether total daily intake and the timing of consumption in relation to exercise maintain adequate carbohydrate substrate for the muscle and central nervous system ("high carbohydrate availability") or whether carbohydrate fuel sources are limiting for the daily exercise programme ("low carbohydrate availability"). Carbohydrate availability is increased by consuming carbohydrate in the hours or days prior to the session, intake during exercise, and refuelling during recovery between sessions. This is important for the competition setting or for high-intensity training where optimal performance is desired. Carbohydrate intake during exercise should be scaled according to the characteristics of the event. During sustained high-intensity sports lasting ~1 h, small amounts of carbohydrate, including even mouth-rinsing, enhance performance via central nervous system effects. While 30-60 g · h(-1) is an appropriate target for sports of longer duration, events >2.5 h may benefit from higher intakes of up to 90 g · h(-1). Products containing special blends of different carbohydrates may maximize absorption of carbohydrate at such high rates. In real life, athletes undertake training sessions with varying carbohydrate availability. Whether implementing additional "train-low" strategies to increase the training adaptation leads to enhanced performance in well-trained individuals is unclear.
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Affiliation(s)
- Louise M Burke
- Department of Sports Medicine, Australian Institute of Sport, Belconnen, ACT, Australia.
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31
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Yeo WK, Carey AL, Burke L, Spriet LL, Hawley JA. Fat adaptation in well-trained athletes: effects on cell metabolism. Appl Physiol Nutr Metab 2011; 36:12-22. [PMID: 21326374 DOI: 10.1139/h10-089] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The performance of prolonged (>90 min), continuous, endurance exercise is limited by endogenous carbohydrate (CHO) stores. Accordingly, for many decades, sports nutritionists and exercise physiologists have proposed a number of diet-training strategies that have the potential to increase fatty acid availability and rates of lipid oxidation and thereby attenuate the rate of glycogen utilization during exercise. Because the acute ingestion of exogenous substrates (primarily CHO) during exercise has little effect on the rates of muscle glycogenolysis, recent studies have focused on short-term (<1-2 weeks) diet-training interventions that increase endogenous substrate stores (i.e., muscle glycogen and lipids) and alter patterns of substrate utilization during exercise. One such strategy is "fat adaptation", an intervention in which well-trained endurance athletes consume a high-fat, low-CHO diet for up to 2 weeks while undertaking their normal training and then immediately follow this by CHO restoration (consuming a high-CHO diet and tapering for 1-3 days before a major endurance event). Compared with an isoenergetic CHO diet for the same intervention period, this "dietary periodization" protocol increases the rate of whole-body and muscle fat oxidation while attenuating the rate of muscle glycogenolysis during submaximal exercise. Of note is that these metabolic perturbations favouring the oxidation of fat persist even in the face of restored endogenous CHO stores and increased exogenous CHO availability. Here we review the current knowledge of some of the potential mechanisms by which skeletal muscle sustains high rates of fat oxidation in the face of high exogenous and endogenous CHO availability.
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Affiliation(s)
- Wee Kian Yeo
- Health Innovations Research Institute, School of Medical Sciences, RMIT University, P.O. Box 71, Bundoora, Victoria 3083, Australia
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Shinohara A, Takakura J, Yamane A, Suzuki M. Effect of the classic 1-week glycogen-loading regimen on fat-loading in rats and humans. J Nutr Sci Vitaminol (Tokyo) 2011; 56:299-304. [PMID: 21228500 DOI: 10.3177/jnsv.56.299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to elucidate the fat-loading effect of the classic 1-wk glycogen-loading regimen histologically in rats and physiologically in humans. In the rat and human studies, an exhaustive swimming exercise and cycle ergometer exercise were loaded on day 1 of a 6-d feeding period, respectively. Thereafter, both the rats and humans were divided into a glycogen-loading regimen consisting of a 3-d high-fat diet and a 3-d high-carbohydrate diet or a 6-d high-carbohydrate diet. After the feeding period in the human study, the human subjects performed a test exercise on day 7 using a cycle ergometer. In the rat study, the intramuscular triglyceride (IMTG) content was 69% greater (p<0.05) after the glycogen-loading regimen than after the high-carbohydrate diet feeding on day 7. In the human study, the respiratory exchange ratios (RER) after the glycogen-loading regimen were 4.9-6% lower than those after the high-carbohydrate diet during the test exercise on day 7 (p<0.05). Our findings suggest that the classical 1-wk glycogen-loading regimen maintained the storage and enhanced the utilization of energy sources during exercise in the skeletal muscle, and that it provides a fat-loading effect, in addition to the glycogen-loading effect, to the skeletal muscle.
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Affiliation(s)
- Akiko Shinohara
- Waseda University School of Human Sciences, Tokorozawa, Japan.
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33
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Haramizu S, Ota N, Hase T, Murase T. Aging-associated changes in physical performance and energy metabolism in the senescence-accelerated mouse. J Gerontol A Biol Sci Med Sci 2011; 66:646-55. [PMID: 21415262 DOI: 10.1093/gerona/glr037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of the study was to clarify the aging-associated changes in physical performance and energy metabolism in senescence-accelerated prone mouse (SAMP1). The endurance of aged SAMP1 was significantly lower by 28% than the age-matched senescence-resistant mouse (SAMR1). Oxygen consumption and fat oxidation in aged SAMP1 were lower by 19% and 22%, respectively. Peroxisome proliferator-activated receptor-γ coactivator-1β and medium-chain acyl coenzyme A dehydrogenase messenger RNA expression was significantly lower in aged SAMP1. Aged SAMP1 exhibited higher plasma glucose, insulin, leptin, and lower adiponectin concentrations. Aged SAMP1 also had higher malondialdehyde levels in plasma and tissues and lower peroxisome proliferator-activated receptor-γ messenger RNA and protein levels in adipose tissue. These results indicate that physical performance and energy expenditure decrease earlier with aging in SAMP1, accompanied by decreased fatty acid catabolism in muscle and liver and increased inflammation and oxidative stress in adipose tissue. SAMP1 could thus be a useful accelerated functional depression model for studying physical performance and energy metabolism.
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Affiliation(s)
- Satoshi Haramizu
- Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan
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Pendergast DR, Meksawan K, Limprasertkul A, Fisher NM. Influence of exercise on nutritional requirements. Eur J Appl Physiol 2010; 111:379-90. [PMID: 21079991 DOI: 10.1007/s00421-010-1710-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2010] [Indexed: 01/05/2023]
Abstract
There is no consensus on the best diet for exercise, as many variables influence it. We propose an approach that is based on the total energy expenditure of exercise and the specific macro- and micronutrients used. di Prampero quantified the impact of intensity and duration on the energy cost of exercise. This can be used to determine the total energy needs and the balance of fats and carbohydrates (CHO). There are metabolic differences between sedentary and trained persons, thus the total energy intake to prevent overfeeding of sedentary persons and underfeeding athletes is important. During submaximal sustained exercise, fat oxidation (FO) plays an important role. This role is diminished and CHO's role increases as exercise intensity increases. At super-maximal exercise intensities, anaerobic glycolysis dominates. In the case of protein and micronutrients, specific recommendations are required. We propose that for submaximal exercise, the balance of CHO and fat favors fat for longer exercise and CHO for shorter exercise, while always maintaining the minimal requirements of each (CHO: 40% and fat: 30%). A case for higher protein (above 15%) as well as creatine supplementation for resistance exercise has been proposed. One may also consider increasing bicarbonate intake for exercise that relies on anaerobic glycolysis, whereas there appears to be little support for antioxidant supplementation. Insuring minimal levels of substrate will prevent exercise intolerance, while increasing some components may increase exercise tolerance.
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Affiliation(s)
- D R Pendergast
- Department of Physiology and Biophysics, 124 Sherman Hall, Center for Research and Education in Special Environments, University at Buffalo, 3435 Main Street, Buffalo, NY 14214, USA.
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35
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Nordsborg NB, Lundby C, Leick L, Pilegaard H. Relative workload determines exercise-induced increases in PGC-1alpha mRNA. Med Sci Sports Exerc 2010; 42:1477-84. [PMID: 20139785 DOI: 10.1249/mss.0b013e3181d2d21c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION The hypothesis that brief intermittent exercise-induced increases in human skeletal muscle metabolic mRNA is dependent on relative workload was investigated. METHODS Trained (n = 10) and untrained (n = 8) subjects performed exhaustive intermittent cycling exercise (4 x 4 min at 85% of VO(2peak), interspersed by 3 min). Trained subjects also performed the intermittent exercise at the same absolute workload as the untrained subjects, corresponding to 70% of VO(2peak) (n = 6). RESULTS Exercise at 85% of V(O2peak) elevated (P < 0.001) venous plasma lactate to 10.1 +/- 0.4 and 10.8 +/- 0.5 mM in the trained and untrained subjects, respectively. Peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) mRNA expression was increased (P < 0.001) approximately four- to fivefold for several hours after exercise in both groups. After exercise at 70% of VO(2peak), venous plasma lactate was less (P < 0.001) elevated (3.1 +/- 0.7 mM) and PGC-1alpha mRNA content was less (P < 0.05) increased (approximately threefold) than after exercise at 85% of VO(2peak). Likewise, pyruvate dehydrogenase kinase 4 and hexokinase II mRNA expressions were increased (P < 0.05) only after exercise performed at 85% of VO(2peak) in the trained subjects. Hypoxia-inducible factor 2alpha mRNA only increased (P < 0.05) 3 h into recovery in trained subjects, with no difference between the 70% and 85% of VO(2peak) trial. No change in hypoxia-inducible factor 1alpha, phosphofructokinase, citrate synthase, or lactate dehydrogenase, heart and muscle isoforms, mRNA expressions was detected after any of the exercise trials. CONCLUSIONS The relative intensity of brief intermittent exercise is of major importance for the exercise-induced increase of several mRNA, including PGC-1alpha.
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Marques C, Motta V, Torres T, Aguila M, Mandarim-de-Lacerda C. Beneficial effects of exercise training (treadmill) on insulin resistance and nonalcoholic fatty liver disease in high-fat fed C57BL/6 mice. Braz J Med Biol Res 2010; 43:467-75. [DOI: 10.1590/s0100-879x2010007500030] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 04/12/2010] [Indexed: 12/13/2022] Open
Affiliation(s)
| | - V.F. Motta
- , Universidade do Estado do Rio de Janeiro, Brasil
| | - T.S. Torres
- , Universidade do Estado do Rio de Janeiro, Brasil
| | - M.B. Aguila
- , Universidade do Estado do Rio de Janeiro, Brasil
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Dumke CL, Nieman DC, Utter AC, Rigby MD, Quindry JC, Triplett NT, McAnulty SR, McAnulty LS. Quercetin's effect on cycling efficiency and substrate utilization. Appl Physiol Nutr Metab 2010; 34:993-1000. [PMID: 20029506 DOI: 10.1139/h09-099] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous evidence suggests that quercetin supplementation increases performance in humans. We examined the effects of 3 weeks of quercetin supplementation on fuel utilization, gross efficiency (GE), and perceived effort during 3 h of cycling over 3 successive days. Forty cyclists were randomized into quercetin and placebo groups and tested for maximal oxygen consumption (53.2 +/- 1.2 and 54.7 +/- 1.1 mL.kg(-1).min(-1)). For 3 weeks following maximal oxygen consumption testing, subjects supplemented either 1000 mg.day(-1) quercetin or placebo during normal training. Following supplementation, subjects cycled at 57% maximum power for 3 h, on 3 successive days, using their own bicycles fitted to CompuTrainer Pro Model trainers (RacerMate, Seattle, Wash.). Metabolic measurements were taken every 30 min for each 3-h ride. Muscle biopsies obtained from the vastus lateralis immediately pre-exercise and postexercise on days 1 and 3 were analyzed for muscle glycogen content. Power output remained constant for all 3 exercise trials, but significant decreases over time were measured for GE, cadence, respiratory exchange ratio, blood glucose, and muscle glycogen. Significant increases were measured for heart rate and volume of oxygen consumption over time. No quercetin treatment effect was observed for any of the outcome measures in this study. These data indicate that GE is reduced during an exhausting 3-h bout of exercise. However, quercetin did not significantly affect any outcomes in these already well-trained subjects.
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Affiliation(s)
- Charles L Dumke
- Department of Health and Human Perfomance, University of Montana, Missoula, MT 59812, USA.
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Nybo L, Pedersen K, Christensen B, Aagaard P, Brandt N, Kiens B. Impact of carbohydrate supplementation during endurance training on glycogen storage and performance. Acta Physiol (Oxf) 2009; 197:117-27. [PMID: 19432594 DOI: 10.1111/j.1748-1716.2009.01996.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Glucose ingestion may improve exercise endurance, but it apparently also influences the transcription rate of several metabolic genes and it alters muscle metabolism during an acute exercise bout. Therefore, we investigated how chronic training responses are affected by glucose ingestion. METHODS In previously untrained males performance and various muscular adaptations were evaluated before and after 8 weeks of supervised endurance training conducted either with (n = 8; CHO group) or without (n = 7; placebo) glucose supplementation. RESULTS The two groups achieved similar improvements in maximal oxygen uptake and peak power output during incremental cycling (both parameters elevated by 17% on average) and both groups lost approximately 3 kg of fat mass during the 8 weeks of training. An equal reduction in respiratory exchange ratio (0.02 units) during submaximal exercise was observed in both groups. Beta-hydroxyacyl-CoA-dehydrogenase activity was increased in both groups, however, to a larger extent in the placebo group (45 +/- 11%) than CHO (23 +/- 9%, P < 0.05). GLUT-4 protein expression increased by 74 +/- 14% in the placebo group and 45 +/- 14% in CHO (both P < 0.05), while resting muscle glycogen increased (P < 0.05) to a larger extent in the placebo group (96 +/- 4%) than CHO (33 +/- 2%). CONCLUSION These results show that carbohydrate supplementation consumed during exercise training influences various muscular training adaptations, but improvements in cardiorespiratory fitness and reductions in fat mass are not affected.
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Affiliation(s)
- L Nybo
- Institute of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
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Haramizu S, Nagasawa A, Ota N, Hase T, Tokimitsu I, Murase T. Different contribution of muscle and liver lipid metabolism to endurance capacity and obesity susceptibility of mice. J Appl Physiol (1985) 2009; 106:871-9. [DOI: 10.1152/japplphysiol.90804.2008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We investigated strain differences in whole body energy metabolism, peripheral lipid metabolism, and energy metabolism-related gene expression and protein levels in BALB/c, C57BL/6J, and A/J mice to evaluate the relationship between endurance capacity, susceptibility to diet-induced obesity, and differences in lipid metabolism in muscle and liver. A high-fat diet significantly increased body weight and fat weight in C57BL/6J mice, but not in BALB/c and A/J mice. The endurance capacity of BALB/c mice was 52% greater than that of C57BL/6J mice and 217% greater than that of A/J mice. The respiratory exchange ratio was lowest in BALB/c mice, higher in C57BL/6J mice, and highest in A/J mice, which inversely correlated with the endurance capacity and fatty acid β-oxidation activity in the muscle. Plasma lactate levels measured immediately after exercise were lowest in BALB/c mice and highest in A/J mice, although there was no difference under resting conditions, suggesting that carbohydrate breakdown is suppressed by enhanced fat utilization during exercise in BALB/c mice. On the other hand, the body weight increase induced by high-fat feeding was related to a reduced whole body energy expenditure, higher respiratory quotient, and lower fatty acid β-oxidation activity in the liver. In addition, β-oxidation activity in the muscle and liver roughly paralleled the mRNA and protein levels of lipid metabolism-related molecules, such as peroxisome proliferator-activated receptor and medium-chain acyl-CoA dehydrogenase, in each tissue. These findings indicate that genetically determined basal muscle and liver lipid metabolism and responsiveness to exercise influence physical performance and obesity susceptibility.
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Ochiai M, Matsuo T. Effects of Short-Term Dietary Change from High-Carbohydrate Diet to High-Fat Diet on Storage, Utilization, and Fatty Acid Composition of Rat Muscle Triglyceride during Swimming Exercise. J Clin Biochem Nutr 2009; 44:168-77. [PMID: 19308271 PMCID: PMC2654473 DOI: 10.3164/jcbn.08-237] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 11/04/2008] [Indexed: 12/04/2022] Open
Abstract
The purpose was to examine the effects of a 3-day dietary change from a high-carbohydrate (C) to high-fat (F) diet on muscle triglyceride (MTG) storage and utilization during the swimming exercise in rats. Rats were meal-fed on either the F diet or the C diet for 11 days. For an additional 3 days, half of the rats in each group were fed the same diets and the other rats were switched to counterpart diets. On the final day, half of the rats in each group were killed before the exercise and the others were killed after the exercise. Serum concentrations of glucose and free fatty acids (FFA) were higher in the post-exercise groups than in the pre-exercise groups. The tissue glycogen contents were lower in the post-exercise groups. However, the MTG contents and fatty acid (FA) compositions were not influenced by the exercise and dietary change. The F diet increased the FFA concentration and slightly increased the MTG content. Moreover, the dietary FA composition influenced the FA composition of the MTG. These results suggest that the exercise did not affect the contents and FA composition of MTG, but that the F diet had an effect on the MTG contents and FA composition.
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Affiliation(s)
- Masaru Ochiai
- Faculty of Agriculture, Kagawa University, Ikenobe, Miki, Kagawa 761-0795, Japan
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Sene-Fiorese M, Duarte FO, Scarmagnani FRR, Cheik NC, Manzoni MSJ, Nonaka KO, Rossi EA, de Oliveira Duarte ACG, Dâmaso AR. Efficiency of intermittent exercise on adiposity and fatty liver in rats fed with high-fat diet. Obesity (Silver Spring) 2008; 16:2217-22. [PMID: 18719640 DOI: 10.1038/oby.2008.339] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE This study aimed to examine and compare the effects of continuous or intermittent exercises on adiposity and fatty liver in rats fed with high-fat diet. METHODS AND PROCEDURES Wistar rats were divided according to diet composition-chow diet (C) or high-fat diet (H)-and kinds of exercise-sedentary (S), continuous (CE), or intermittent (IE) exercises. The CE group swam 90 min/day, and the IE group swam 3 x 30 min/day (at 4-h intervals between sessions); both groups exercised 5 days/week during 8 weeks. Body weight and food intake were recorded daily. Lipogenesis rate in vivo was determined by the incorporation of (3)H(2)O into saponified lipids in retroperitoneal (RET), epididymal (EPI), and visceral (VIS) white adipose tissues, brown adipose tissue (BAT), liver (L), and gastrocnemius muscle (GAST) using the gravimetric method. Total cholesterol, high-density lipoprotein (HDL)-cholesterol, and triacylglycerol (TG) were analyzed. RESULTS The major finding of this study is that IE was more efficient than CE in reducing the adverse effects of high-fat diet and sedentarism. There was an improvement in the lipid profile and a reduction in food intake, body weight gain, visceral and central adiposity, and fatty liver, contributing to the control of obesity and other comorbidities, including nonalcoholic fat liver diseases. DISCUSSION Earlier studies have discussed the effects of diet consumption on adiposity and their relation to chronic diseases and obesity. This study discusses the effects of high-fat diet consumption and the different kinds of exercise on weight gain, adiposity, fatty liver, and lipid profile in rats. The results may depend on the exercise, time of each session, age, gender, and experimental period.
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Affiliation(s)
- Marcela Sene-Fiorese
- Department of Physical Education, Center of Biological and Health Sciences, Federal University of São Carlos, São Paulo, Brazil
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White AM, Johnston CS, Swan PD, Tjonn SL, Sears B. Blood ketones are directly related to fatigue and perceived effort during exercise in overweight adults adhering to low-carbohydrate diets for weight loss: a pilot study. ACTA ACUST UNITED AC 2007; 107:1792-6. [PMID: 17904939 DOI: 10.1016/j.jada.2007.07.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Indexed: 11/16/2022]
Abstract
Ketogenic diets have been associated with reductions in free-living physical activity, a response that can be counterproductive in individuals trying to lose weight. To explore whether popular low-carbohydrate diets might impact the desire to exercise by raising blood ketone concentrations, fatigue and perceived effort during exercise were compared in untrained, overweight adults adhering to a ketogenic low-carbohydrate diet or to a control diet low in carbohydrate, but not ketogenic (5%, 65%, and 30% or 40%, 30%, and 30% of energy from carbohydrate, fat, and protein, respectively). In this prospective, randomized, 2-week pilot study, all meals and snacks were provided to subjects, and energy intake was strictly controlled to provide approximately 70% of that needed for weight maintenance. At baseline and at the end of week 2, exercise testing was conducted in fasting participants. Weight loss and the reductions in fat mass did not differ by group during the trial. At week 2, blood beta-hydroxybutyrate concentrations were 3.6-fold greater for the ketogenic vs nonketogenic group (P=0.018) and correlated significantly with perceived exercise effort (r2=0.22, P=0.049). Blood beta-hydroxybutyrate was also significantly correlated to feelings of "fatigue" (r=0.458, P=0.049) and to "total mood disturbance" (r=0.551, P=0.015) while exercising. These pilot data indicate that ketogenic, low-carbohydrate diets enhance fatigability and can reduce the desire to exercise in free-living individuals.
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Affiliation(s)
- Andrea M White
- Department of Nutrition, Arizona State University, Mesa 85212, USA
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Petersen M, Taylor MA, Saris WHM, Verdich C, Toubro S, Macdonald I, Rössner S, Stich V, Guy-Grand B, Langin D, Martinez JA, Pedersen O, Holst C, Sørensen TIA, Astrup A. Randomized, multi-center trial of two hypo-energetic diets in obese subjects: high- versus low-fat content. Int J Obes (Lond) 2005; 30:552-60. [PMID: 16331300 DOI: 10.1038/sj.ijo.0803186] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To investigate whether a hypo-energetic low-fat diet is superior to a hypo-energetic high-fat diet for the treatment of obesity. DESIGN Open-label, 10-week dietary intervention comparing two hypo-energetic (-600 kcal/day) diets with a fat energy percent of 20-25 or 40-45. SUBJECTS Obese (BMI >or=30 kg/m(2)) adult subjects (n = 771), from eight European centers. MEASUREMENTS Body weight loss, dropout rates, proportion of subjects who lost more than 10% of initial body weight, blood lipid profile, insulin and glucose. RESULTS The dietary fat energy percent was 25% in the low-fat group and 40% in the high-fat group (mean difference: 16 (95% confidence interval (CI) 15-17)%). Average weight loss was 6.9 kg in the low-fat group and 6.6 kg in the high-fat group (mean difference: 0.3 (95% CI -0.2 to 0.8) kg). Dropout was 13.6% (n = 53) in the low-fat group and 18.3% (n = 70) in the high-fat group (P=0.001). Among completers, more subjects lost >10% in the low-fat group than in the high-fat group ((20.8%, n = 70) versus (14.7%, n = 46), P = 0.02). Fasting plasma total, low-density lipoprotein- and high-density lipoprotein-cholesterol decreased in both groups, but more so in the low-fat group than in the high-fat group. Fasting plasma insulin and glucose were lowered equally by both diets. CONCLUSIONS The low-fat diet produced similar mean weight loss as the high-fat diet, but resulted in more subjects losing >10% of initial body weight and fewer dropouts. Both diets produced favorable changes in fasting blood lipids, insulin and glucose.
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Affiliation(s)
- M Petersen
- Institute of Human Nutrition, The Royal Veterinary and Agricultural University, Copenhagen, Denmark
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Havemann L, West SJ, Goedecke JH, Macdonald IA, St Clair Gibson A, Noakes TD, Lambert EV. Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. J Appl Physiol (1985) 2005; 100:194-202. [PMID: 16141377 DOI: 10.1152/japplphysiol.00813.2005] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to investigate the effect of a high-fat diet (HFD) followed by 1 day of carbohydrate (CHO) loading on substrate utilization, heart rate variability (HRV), effort perception [rating or perceived exertion (RPE)], muscle recruitment [electromyograph (EMG)], and performance during a 100-km cycling time trial. In this randomized single-blind crossover study, eight well-trained cyclists completed two trials, ingesting either a high-CHO diet (HCD) (68% CHO energy) or an isoenergetic HFD (68% fat energy) for 6 days, followed by 1 day of CHO loading (8-10 g CHO/kg). Subjects completed a 100-km time trial on day 1 and a 1-h cycle at 70% of peak oxygen consumption on days 3, 5, and 7, during which resting HRV and resting and exercising respiratory exchange ratio (RER) were measured. On day 8, subjects completed a 100-km performance time trial, during which blood samples were drawn and EMG was recorded. Ingestion of the HFD reduced RER at rest (P < 0.005) and during exercise (P < 0.01) and increased plasma free fatty acid levels (P < 0.01), indicating increased fat utilization. There was a tendency for the low-frequency power component of HRV to be greater for HFD-CHO (P = 0.056), suggestive of increased sympathetic activation. Overall 100-km time-trial performance was not different between diets; however, 1-km sprint power output after HFD-CHO was lower (P < 0.05) compared with HCD-CHO. Despite a reduced power output with HFD-CHO, RPE, heart rate, and EMG were not different between trials. In conclusion, the HFD-CHO dietary strategy increased fat oxidation, but compromised high intensity sprint performance, possibly by increased sympathetic activation or altered contractile function.
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Affiliation(s)
- L Havemann
- University of Cape Town/Medical Research Council Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, South Africa
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van Loon LJC. Use of intramuscular triacylglycerol as a substrate source during exercise in humans. J Appl Physiol (1985) 2005; 97:1170-87. [PMID: 15358749 DOI: 10.1152/japplphysiol.00368.2004] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Fat and carbohydrate are the principal substrates that fuel aerobic ATP synthesis in skeletal muscle. Most endogenous fat is stored as triacylglycerol in subcutaneous and deep visceral adipose tissue. Smaller quantities of triacylglycerol are deposited as lipid droplets inside skeletal muscle fibers. The potential role of intramyocellular triacylglycerol (IMTG) as a substrate source during exercise in humans has recently regained much of its interest because of the proposed functional relationship between IMTG accumulation and the development of skeletal muscle insulin resistance. Exercise likely represents an effective means to prevent excess IMTG accretion by stimulating its rate of oxidation. However, there is much controversy on the actual contribution of the IMTG pool as a substrate source during exercise. The apparent discrepancy in the literature likely stems from methodological difficulties that have been associated with the methods used to estimate IMTG oxidation during exercise. However, recent studies using stable isotope methodology, 1H-magnetic resonance spectroscopy, and electron and/or immunofluorescence microscopy all support the contention that the IMTG pool can function as an important substrate source during exercise. Although more research is warranted, IMTG mobilization and/or oxidation during exercise seem to be largely determined by exercise intensity, exercise duration, macronutrient composition of the diet, training status, gender, and/or age. In addition, indirect evidence suggests that the capacity to mobilize and/or oxidize IMTG is substantially impaired in an obese and/or Type 2 diabetic state. As we now become aware that skeletal muscle has an enormous capacity to oxidize IMTG stores during exercise, more research is warranted to develop combined exercise, nutritional, and/or pharmacological interventions to effectively stimulate IMTG oxidation in sedentary, obese, and/or Type 2 diabetes patients.
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Affiliation(s)
- Luc J C van Loon
- Nutrition Research Institute Maastricht (NUTRIM Dept. of Human Biology, Maastricht Univ., PO Box 616, 6200 MD Maastricht, The Netherlands.
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Heck AL, Barroso CS, Callie ME, Bray MS. Gene-nutrition interaction in human performance and exercise response. Nutrition 2005; 20:598-602. [PMID: 15212740 DOI: 10.1016/j.nut.2004.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent advances in human performance research have revealed new insight into the many factors that influence how an individual responds to exercise training. Response to exercise interventions is often highly variable among individuals, however, and exercise response may be mediated in large part by variation in genes and nutrition and by gene-environment interactions. It is well established that the quality and quantity of nutritional intake play a critical role in response to training and in athletic performance. The body's adaptation to exercise is also the result of changes in expression of genes mediated not only by exercise but by multiple factors, including the interaction between exercise, components of dietary intake, and genetic variation. This review explores the effects of genetic variation and gene-nutrition interactions in response to exercise training and athletic performance.
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Affiliation(s)
- Amy L Heck
- Graduate School of Biomedical Sciences, School of Public Health, University of Texas Health Science Center, Houston, Texas 77030, USA
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Abstract
Interventions aimed at increasing fat metabolism could potentially reduce the symptoms of metabolic diseases such as obesity and type 2 diabetes and may have tremendous clinical relevance. Hence, an understanding of the factors that increase or decrease fat oxidation is important. Exercise intensity and duration are important determinants of fat oxidation. Fat oxidation rates increase from low to moderate intensities and then decrease when the intensity becomes high. Maximal rates of fat oxidation have been shown to be reached at intensities between 59% and 64% of maximum oxygen consumption in trained individuals and between 47% and 52% of maximum oxygen consumption in a large sample of the general population. The mode of exercise can also affect fat oxidation, with fat oxidation being higher during running than cycling. Endurance training induces a multitude of adaptations that result in increased fat oxidation. The duration and intensity of exercise training required to induce changes in fat oxidation is currently unknown. Ingestion of carbohydrate in the hours before or on commencement of exercise reduces the rate of fat oxidation significantly compared with fasted conditions, whereas fasting longer than 6 h optimizes fat oxidation. Fat oxidation rates have been shown to decrease after ingestion of high-fat diets, partly as a result of decreased glycogen stores and partly because of adaptations at the muscle level.
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Affiliation(s)
- Juul Achten
- School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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De Bock K, Richter EA, Russell AP, Eijnde BO, Derave W, Ramaekers M, Koninckx E, Léger B, Verhaeghe J, Hespel P. Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans. J Physiol 2005; 564:649-60. [PMID: 15705646 PMCID: PMC1464435 DOI: 10.1113/jphysiol.2005.083170] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The effects were compared of exercise in the fasted state and exercise with a high rate of carbohydrate intake on intramyocellular triglyceride (IMTG) and glycogen content of human muscle. Using a randomized crossover study design, nine young healthy volunteers participated in two experimental sessions with an interval of 3 weeks. In each session subjects performed 2 h of constant-load bicycle exercise ( approximately 75% ), followed by 4 h of controlled recovery. On one occasion they exercised after an overnight fast (F), and on the other (CHO) they received carbohydrates before ( approximately 150 g) and during (1 g (kg bw)(-1) h(-1)) exercise. In both conditions, subjects ingested 5 g carbohydrates per kg body weight during recovery. Fibre type-specific relative IMTG content was determined by Oil red O staining in needle biopsies from m. vastus lateralis before, immediately after and 4 h after exercise. During F but not during CHO, the exercise bout decreased IMTG content in type I fibres from 18 +/- 2% to 6 +/- 2% (P = 0.007) area lipid staining. Conversely, during recovery, IMTG in type I fibres decreased from 15 +/- 2% to 10 +/- 2% in CHO, but did not change in F. Neither exercise nor recovery changed IMTG in type IIa fibres in any experimental condition. Exercise-induced net glycogen breakdown was similar in F and CHO. However, compared with CHO (11.0 +/- 7.8 mmol kg(-1) h(-1)), mean rate of postexercise muscle glycogen resynthesis was 3-fold greater in F (32.9 +/- 2.7 mmol kg(-1) h(-1), P = 0.01). Furthermore, oral glucose loading during recovery increased plasma insulin markedly more in F (+46.80 microU ml(-1)) than in CHO (+14.63 microU ml(-1), P = 0.02). We conclude that IMTG breakdown during prolonged submaximal exercise in the fasted state takes place predominantly in type I fibres and that this breakdown is prevented in the CHO-fed state. Furthermore, facilitated glucose-induced insulin secretion may contribute to enhanced muscle glycogen resynthesis following exercise in the fasted state.
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Affiliation(s)
- K De Bock
- Exercise Physiology and Biomechanics Laboratory, Faculty of Kinesiology and Rehabilitation Sciences, K.U.Leuven, Tervuursevest 101, B-3001 Leuven (Heverlee), Belgium
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Peters SJ, LeBlanc PJ. Metabolic aspects of low carbohydrate diets and exercise. Nutr Metab (Lond) 2004; 1:7. [PMID: 15507161 PMCID: PMC524355 DOI: 10.1186/1743-7075-1-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Accepted: 09/30/2004] [Indexed: 01/30/2023] Open
Abstract
Following a low carbohydrate diet, there is a shift towards more fat and less carbohydrate oxidation to provide energy to skeletal muscle, both at rest and during exercise. This review summarizes recent work on human skeletal muscle carbohydrate and fat metabolic adaptations to a low carbohydrate diet, focusing mainly on pyruvate dehydrogenase and pyruvate dehydrogenase kinase, and how these changes relate to the capacity for carbohydrate oxidation during exercise.
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Affiliation(s)
- Sandra J Peters
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1
| | - Paul J LeBlanc
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1
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Burke LM, Hawley JA. Effects of short-term fat adaptation on metabolism and performance of prolonged exercise. Med Sci Sports Exerc 2002; 34:1492-8. [PMID: 12218744 DOI: 10.1097/00005768-200209000-00015] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The concept of manipulating an individuals habitual diet before an exercise bout in an attempt to modify patterns of fuel substrate utilization and enhance subsequent exercise capacity is not new. Modern studies have focused on nutritional and training strategies aimed to optimize endogenous carbohydrate (CHO) stores while simultaneously maximizing the capacity for fat oxidation during continuous, submaximal (60-70% of maximal O(2) uptake [(.)VO(2max)] exercise. Such "nutritional periodization" typically encompasses 5-6 d of a high-fat diet (60-70% E) followed by 1-2 d of high-CHO intake (70-80% E; CHO restoration). Despite the brevity of the adaptation period, ingestion of a high-fat diet by endurance-trained athletes results in substantially higher rates of fat oxidation and concomitant muscle glycogen sparing during submaximal exercise compared with an isoenergetic high-CHO diet. Higher rates of fat oxidation during exercise persist even under conditions in which CHO availability is increased, either by having athletes consume a high-CHO meal before exercise and/or ingest glucose solutions during exercise. Yet, despite marked changes in the patterns of fuel utilization that favor fat oxidation, fat-adaptation/CHO restoration strategies do not provide clear benefits to the performance of prolonged endurance exercise.
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Affiliation(s)
- Louise M Burke
- Department of Sports Nutrition, Australian Institute of Sport, PO Box 176, Belconnen, A.C.T. 2616, Australia.
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