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Maunder E, King A, Rothschild JA, Brick MJ, Leigh WB, Hedges CP, Merry TL, Kilding AE. Locally applied heat stress during exercise training may promote adaptations to mitochondrial enzyme activities in skeletal muscle. Pflugers Arch 2024; 476:939-948. [PMID: 38446167 PMCID: PMC11139708 DOI: 10.1007/s00424-024-02939-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/22/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024]
Abstract
There is some evidence for temperature-dependent stimulation of mitochondrial biogenesis; however, the role of elevated muscle temperature during exercise in mitochondrial adaptation to training has not been studied in humans in vivo. The purpose of this study was to determine the role of elevating muscle temperature during exercise in temperate conditions through the application of mild, local heat stress on mitochondrial adaptations to endurance training. Eight endurance-trained males undertook 3 weeks of supervised cycling training, during which mild (~ 40 °C) heat stress was applied locally to the upper-leg musculature of one leg during all training sessions (HEAT), with the contralateral leg serving as the non-heated, exercising control (CON). Vastus lateralis microbiopsies were obtained from both legs before and after the training period. Training-induced increases in complex I (fold-change, 1.24 ± 0.33 vs. 1.01 ± 0.49, P = 0.029) and II (fold-change, 1.24 ± 0.33 vs. 1.01 ± 0.49, P = 0.029) activities were significantly larger in HEAT than CON. No significant effects of training, or interactions between local heat stress application and training, were observed for complex I-V or HSP70 protein expressions. Our data provides partial evidence to support the hypothesis that elevating local muscle temperature during exercise augments training-induced adaptations to mitochondrial enzyme activity.
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Affiliation(s)
- Ed Maunder
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand.
| | - Andrew King
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Jeffrey A Rothschild
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Matthew J Brick
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Warren B Leigh
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Andrew E Kilding
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
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El Ouali EM, Kartibou J, Del Coso J, El Makhzen B, Bouguenouch L, El Harane S, Taib B, Weiss K, Knechtle B, Mesfioui A, Zouhal H. Genotypic and Allelic Distribution of the CD36 rs1761667 Polymorphism in High-Level Moroccan Athletes: A Pilot Study. Genes (Basel) 2024; 15:419. [PMID: 38674354 PMCID: PMC11049038 DOI: 10.3390/genes15040419] [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: 03/06/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Previous studies have shown that variations in the CD36 gene may affect phenotypes associated with fat metabolism as the CD36 protein facilitates the transport of fatty acids to the mitochondria for oxidation. However, no previous study has tested whether variations in the CD36 gene are associated with sports performance. We investigated the genotypic and allelic distribution of the single-nucleotide polymorphism (SNP) rs1761667 in the CD36 gene in elite Moroccan athletes (cyclists and hockey players) in comparison with healthy non-athletes of the same ethnic origin. Forty-three Moroccan elite male athletes (nineteen cyclists and twenty-four field hockey players) belonging to the national teams of their respective sports (athlete group) were compared to twenty-eight healthy, active, male university students (control group). Genotyping of the CD36 rs1761667 (G>A) SNP was performed via polymerase chain reaction (PCR) and Sanger sequencing. A chi-square (χ2) test was used to assess the Hardy-Weinberg equilibrium (HWE) and to compare allele and genotype frequencies in the "athlete" and "control" groups. The genotypic distribution of the CD36 rs1761667 polymorphism was similar in elite athletes (AA: 23.81, AG: 59.52, and GG: 16.67%) and controls (AA: 19.23, AG: 69.23, and GG: 11.54%; χ2 = 0.67, p = 0.71). However, the genotypic distribution of the CD36 rs1761667 polymorphism was different between cyclists (AA: 0.00, AG: 72.22, and GG: 27.78%) and hockey players (AA: 41.67, AG: 50.00, and GG: 8.33%; χ2 = 10.69, p = 0.004). Specifically, the frequency of the AA genotype was significantly lower in cyclists than in hockey players (p = 0.02). In terms of allele frequency, a significant difference was found between cyclists versus field hockey players (χ2 = 7.72, p = 0.005). Additionally, there was a predominance of the recessive model in cyclists over field hockey players (OR: 0.00, 95% CI: 0.00-0.35, p = 0.002). Our study shows a significant difference between cyclists and field hockey players in terms of the genotypic and allelic frequency of the SNP rs1761667 of the CD36 gene. This divergence suggests a probable association between genetic variations in the CD36 gene and the type of sport in elite Moroccan athletes.
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Affiliation(s)
- El Mokhtar El Ouali
- Laboratory of Biology and Health, Department of Biology, Ibn Tofail University, Kenitra 14000, Morocco; (E.M.E.O.); (J.K.); (A.M.)
| | - Jihan Kartibou
- Laboratory of Biology and Health, Department of Biology, Ibn Tofail University, Kenitra 14000, Morocco; (E.M.E.O.); (J.K.); (A.M.)
| | - Juan Del Coso
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Fuenlabrada, Spain
| | - Badreddine El Makhzen
- Medical Genetics Unit, Central Laboratory, CHU Hassan II, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdellah University, Fez 30040, Morocco; (B.E.M.); (L.B.)
| | - Laila Bouguenouch
- Medical Genetics Unit, Central Laboratory, CHU Hassan II, Faculty of Medicine, Pharmacy and Dentistry, Sidi Mohamed Ben Abdellah University, Fez 30040, Morocco; (B.E.M.); (L.B.)
| | - Sanae El Harane
- Institute of Sports Professions, Ibn Tofail University, Kenitra 14000, Morocco;
| | - Bouchra Taib
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland;
| | - Katja Weiss
- Institute of Primary Care, University of Zurich, 8032 Zurich, Switzerland; (K.W.); (B.K.)
| | - Beat Knechtle
- Institute of Primary Care, University of Zurich, 8032 Zurich, Switzerland; (K.W.); (B.K.)
- Medbase St. Gallen Am Vadianplatz, 9000 St. Gallen, Switzerland
| | - Abdelhalem Mesfioui
- Laboratory of Biology and Health, Department of Biology, Ibn Tofail University, Kenitra 14000, Morocco; (E.M.E.O.); (J.K.); (A.M.)
| | - Hassane Zouhal
- M2S (Laboratoire Mouvement, Sport et Santé)—EA 1274, University of Rennes, 35000 Rennes, France
- Institut International des Sciences du Sport (2I2S), 35850 Irodouër, France
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Maunder E, Rothschild JA, Fritzen AM, Jordy AB, Kiens B, Brick MJ, Leigh WB, Chang WL, Kilding AE. Skeletal muscle proteins involved in fatty acid transport influence fatty acid oxidation rates observed during exercise. Pflugers Arch 2023; 475:1061-1072. [PMID: 37464190 PMCID: PMC10409849 DOI: 10.1007/s00424-023-02843-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/06/2023] [Accepted: 07/12/2023] [Indexed: 07/20/2023]
Abstract
Several proteins are implicated in transmembrane fatty acid transport. The purpose of this study was to quantify the variation in fatty acid oxidation rates during exercise explained by skeletal muscle proteins involved in fatty acid transport. Seventeen endurance-trained males underwent a (i) fasted, incremental cycling test to estimate peak whole-body fatty acid oxidation rate (PFO), (ii) resting vastus lateralis microbiopsy, and (iii) 2 h of fed-state, moderate-intensity cycling to estimate whole-body fatty acid oxidation during fed-state exercise (FO). Bivariate correlations and stepwise linear regression models of PFO and FO during 0-30 min (early FO) and 90-120 min (late FO) of continuous cycling were constructed using muscle data. To assess the causal role of transmembrane fatty acid transport in fatty acid oxidation rates during exercise, we measured fatty acid oxidation during in vivo exercise and ex vivo contractions in wild-type and CD36 knock-out mice. We observed a novel, positive association between vastus lateralis FATP1 and PFO and replicated work reporting a positive association between FABPpm and PFO. The stepwise linear regression model of PFO retained CD36, FATP1, FATP4, and FABPpm, explaining ~87% of the variation. Models of early and late FO explained ~61 and ~65% of the variation, respectively. FATP1 and FATP4 emerged as contributors to models of PFO and FO. Mice lacking CD36 had impaired whole-body and muscle fatty acid oxidation during exercise and muscle contractions, respectively. These data suggest that substantial variation in fatty acid oxidation rates during exercise can be explained by skeletal muscle proteins involved in fatty acid transport.
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Affiliation(s)
- Ed Maunder
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand.
| | - Jeffrey A Rothschild
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Andreas M Fritzen
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andreas B Jordy
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Matthew J Brick
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Warren B Leigh
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Wee-Leong Chang
- Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Andrew E Kilding
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
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Ramos-Jiménez A, Zavala-Lira RA, Moreno-Brito V, González-Rodríguez E. FAT/CD36 Participation in Human Skeletal Muscle Lipid Metabolism: A Systematic Review. J Clin Med 2022; 12:jcm12010318. [PMID: 36615118 PMCID: PMC9821548 DOI: 10.3390/jcm12010318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/16/2022] [Accepted: 12/26/2022] [Indexed: 01/03/2023] Open
Abstract
Fatty acid translocase/cluster of differentiation 36 (FAT/CD36) is a multifunctional membrane protein activated by a high-fat diet, physical exercise, fatty acids (FAs), leptin, and insulin. The principal function of FAT/CD36 is to facilitate the transport of long-chain fatty acids through cell membranes such as myocytes, adipocytes, heart, and liver. Under high-energy expenditure, the different isoforms of FAT/CD36 in the plasma membrane and mitochondria bind to the mobilization and oxidation of FAs. Furthermore, FAT/CD36 is released in its soluble form and becomes a marker of metabolic dysfunction. Studies with healthy animals and humans show that physical exercise and a high-lipid diet increase FAT/CD36 expression and caloric expenditure. However, several aspects such as obesity, diabetes, Single Nucleotide polymorphisms (SNPs), and oxidative stress affect the normal FAs metabolism and function of FAT/CD36, inducing metabolic disease. Through a comprehensive systematic review of primary studies, this work aimed to document molecular mechanisms related to FAT/CD36 in FAs oxidation and trafficking in skeletal muscle under basal conditions, physical exercise, and diet in healthy individuals.
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Affiliation(s)
- Arnulfo Ramos-Jiménez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del PRONAF y Estocolmo S/N, Ciudad Juárez 32310, Chihuahua, Mexico
- Correspondence:
| | - Ruth A. Zavala-Lira
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del PRONAF y Estocolmo S/N, Ciudad Juárez 32310, Chihuahua, Mexico
| | - Verónica Moreno-Brito
- Facultad de Medicina, Circuito Universitario Campus II, Universidad Autónoma de Chihuahua, Chihuahua 31124, Chihuahua, Mexico
| | - Everardo González-Rodríguez
- Facultad de Medicina, Circuito Universitario Campus II, Universidad Autónoma de Chihuahua, Chihuahua 31124, Chihuahua, Mexico
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Prolonged cycling reduces power output at the moderate-to-heavy intensity transition. Eur J Appl Physiol 2022; 122:2673-2682. [PMID: 36127418 PMCID: PMC9488873 DOI: 10.1007/s00421-022-05036-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/02/2022] [Indexed: 12/01/2022]
Abstract
Purpose To determine the effect of prolonged exercise on moderate-to-heavy intensity transition power output and heart rate. Methods Fourteen endurance-trained cyclists and triathletes took part in the present investigation (13 males, 1 female, V·O2peak 59.9 ± 6.8 mL.kg−1.min−1). Following a characterisation trial, participants undertook a five-stage incremental step test to determine the power output and heart rate at the moderate-to-heavy intensity transition before and after two hours of cycling at 90% of the estimated power output at first ventilatory threshold (VT1). Results Power output at the moderate-to-heavy intensity transition significantly decreased following acute prolonged exercise when determined using expired gases (VT1, 217 ± 42 W vs. 196 ± 42 W, P < 0.0001) and blood lactate concentrations (LoglogLT, 212 ± 47 W vs. 190 ± 47 W, P = 0.004). This was attributable to loss of efficiency (VT1, -8 ± 10 W; LoglogLT, − 7 ± 9 W) and rates of metabolic energy expenditure at the transition (VT1, − 14 ± 11 W; LoglogLT, − 15 ± 22 W). The heart rate associated with the moderate-to-heavy intensity transition increased following acute prolonged exercise (VT1, 142 ± 9 beats.min−1 vs. 151 ± 12 beats.min−1, P < 0.001; LoglogLT, 140 ± 13 beats.min−1 vs. 150 ± 15 beats.min−1, P = 0.006). Conclusion These results demonstrate the external work output at the moderate-to-heavy intensity transition decreases during prolonged exercise due to decreased efficiency and rates of metabolic energy expenditure, but the associated heart rate increases. Therefore, individual assessments of athlete ‘durability’ are warranted. Supplementary Information The online version contains supplementary material available at 10.1007/s00421-022-05036-9.
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Beyond the Calorie Paradigm: Taking into Account in Practice the Balance of Fat and Carbohydrate Oxidation during Exercise? Nutrients 2022; 14:nu14081605. [PMID: 35458167 PMCID: PMC9027421 DOI: 10.3390/nu14081605] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 02/04/2023] Open
Abstract
Recent literature shows that exercise is not simply a way to generate a calorie deficit as an add-on to restrictive diets but exerts powerful additional biological effects via its impact on mitochondrial function, the release of chemical messengers induced by muscular activity, and its ability to reverse epigenetic alterations. This review aims to summarize the current literature dealing with the hypothesis that some of these effects of exercise unexplained by an energy deficit are related to the balance of substrates used as fuel by the exercising muscle. This balance of substrates can be measured with reliable techniques, which provide information about metabolic disturbances associated with sedentarity and obesity, as well as adaptations of fuel metabolism in trained individuals. The exercise intensity that elicits maximal oxidation of lipids, termed LIPOXmax, FATOXmax, or FATmax, provides a marker of the mitochondrial ability to oxidize fatty acids and predicts how much fat will be oxidized over 45–60 min of low- to moderate-intensity training performed at the corresponding intensity. LIPOXmax is a reproducible parameter that can be modified by many physiological and lifestyle influences (exercise, diet, gender, age, hormones such as catecholamines, and the growth hormone-Insulin-like growth factor I axis). Individuals told to select an exercise intensity to maintain for 45 min or more spontaneously select a level close to this intensity. There is increasing evidence that training targeted at this level is efficient for reducing fat mass, sparing muscle mass, increasing the ability to oxidize lipids during exercise, lowering blood pressure and low-grade inflammation, improving insulin secretion and insulin sensitivity, reducing blood glucose and HbA1c in type 2 diabetes, and decreasing the circulating cholesterol level. Training protocols based on this concept are easy to implement and accept in very sedentary patients and have shown an unexpected efficacy over the long term. They also represent a useful add-on to bariatric surgery in order to maintain and improve its weight-lowering effect. Additional studies are required to confirm and more precisely analyze the determinants of LIPOXmax and the long-term effects of training at this level on body composition, metabolism, and health.
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Blasco-Lafarga C, Monferrer-Marín J, Roldán A, Monteagudo P, Chulvi-Medrano I. Metabolic Flexibility and Mechanical Efficiency in Women Over-60. Front Physiol 2022; 13:869534. [PMID: 35464093 PMCID: PMC9019701 DOI: 10.3389/fphys.2022.869534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/21/2022] [Indexed: 01/12/2023] Open
Abstract
Purpose: Aging deteriorates metabolic flexibility (MF). Moreover, recent studies show that glycolysis is barely increased despite impoverished lipid metabolism, in addition to increased relevance of muscle power in older adults. This study aims to analyze MF, i.e., fat and carbohydrates oxidation rates (FATox and CHOox), and the point of maximal fat oxidation (MFO), in a group of active women over-60. It also aims to delve into the role of power production and mechanical efficiency regarding MF. This will help to decipher their metabolic behavior in response to increasing intensity. Methods: Twenty-nine women (66.13 ± 5.62 years) performed a submaximal graded cycling test, increasing 10 W each 3-min15-s, from 30 W to the second ventilatory threshold (VT2). Muscle power was adjusted with a Saris-H3 roller, together with a continuous gas analysis by indirect calorimetry (Cosmed K4b2). Pre and post-test blood lactate (BLa) samples were included. Frayn’s equations, MFO and CHOoxpeak (mg/min/kg FFM) were considered for MF analysis (accounting for average VO2 and VCO2 in each last 60-s), whilst delta and gross efficiencies (DE%, GE%), and exercise economy (EC), were added for Mechanical Efficiency. Mean comparisons regarding intensities 60, 80 and 100% at VT2, completed the study together with correlation analysis among the main variables. Results: MFO and CHOoxpeak were small (6.35 ± 3.59 and 72.79 ± 34.76 g/min/kgFFM respectively) for a reduced muscle power (78.21 ± 15.84 W). Notwithstanding, GE% and EC increased significantly (p < 0.01) with exercise intensity. Importantly, coefficients of variation were very large confirming heterogeneity. Whilst muscle power outcomes correlated significantly (p < 0.01) with MFO (r = 0.66) and age (r = −0.62), these latter failed to be associated. Only GE% correlated to CHOoxpeak (r = −0.61, p < 0.01) regarding mechanical efficiency. Conclusions: Despite being active, women over-60 confirmed impaired substrates switching in response to exercise, from both FAT and CHO pathways. This limits their power production affecting exercise capacity. Our data suggest that decreased power with age has a key role above age per se in this metabolic inflexibility. Vice versa, increasing power seems to protect from mitochondrial dysfunction with aging. New studies will confirm if this higher efficiency when coming close to VT2, where GE is the more informative variable, might be a protective compensatory mechanism.
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Affiliation(s)
- Cristina Blasco-Lafarga
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
- *Correspondence: Cristina Blasco-Lafarga, ; Jordi Monferrer-Marín,
| | - Jordi Monferrer-Marín
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
- *Correspondence: Cristina Blasco-Lafarga, ; Jordi Monferrer-Marín,
| | - Ainoa Roldán
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
| | - Pablo Monteagudo
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
- Department of Education and Specific Didactics, Jaume I University, Castellon, Spain
| | - Ivan Chulvi-Medrano
- Sport Performance and Physical Fitness Research Group (UIRFIDE), Physical Education and Sport Department, University of Valencia, Valencia, Spain
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Biomarkers and genetic polymorphisms associated with maximal fat oxidation during physical exercise: implications for metabolic health and sports performance. Eur J Appl Physiol 2022; 122:1773-1795. [PMID: 35362801 DOI: 10.1007/s00421-022-04936-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/18/2022] [Indexed: 11/03/2022]
Abstract
The maximal fat oxidation rate (MFO) assessed during a graded exercise test is a remarkable physiological indicator associated with metabolic flexibility, body weight loss and endurance performance. The present review considers existing biomarkers related to MFO, highlighting the validity of maximal oxygen uptake and free fatty acid availability for predicting MFO in athletes and healthy individuals. Moreover, we emphasize the role of different key enzymes and structural proteins that regulate adipose tissue lipolysis (i.e., triacylglycerol lipase, hormone sensitive lipase, perilipin 1), fatty acid trafficking (i.e., fatty acid translocase cluster of differentiation 36) and skeletal muscle oxidative capacity (i.e., citrate synthase and mitochondrial respiratory chain complexes II-V) on MFO variation. Likewise, we discuss the association of MFO with different polymorphism on the ACE, ADRB3, AR and CD36 genes, identifying prospective studies that will help to elucidate the mechanisms behind such associations. In addition, we highlight existing evidence that contradict the paradigm of a higher MFO in women due to ovarian hormones activity and highlight current gaps regarding endocrine function and MFO relationship.
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New Horizons in Carbohydrate Research and Application for Endurance Athletes. Sports Med 2022; 52:5-23. [PMID: 36173597 PMCID: PMC9734239 DOI: 10.1007/s40279-022-01757-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2022] [Indexed: 12/15/2022]
Abstract
The importance of carbohydrate as a fuel source for exercise and athletic performance is well established. Equally well developed are dietary carbohydrate intake guidelines for endurance athletes seeking to optimize their performance. This narrative review provides a contemporary perspective on research into the role of, and application of, carbohydrate in the diet of endurance athletes. The review discusses how recommendations could become increasingly refined and what future research would further our understanding of how to optimize dietary carbohydrate intake to positively impact endurance performance. High carbohydrate availability for prolonged intense exercise and competition performance remains a priority. Recent advances have been made on the recommended type and quantity of carbohydrates to be ingested before, during and after intense exercise bouts. Whilst reducing carbohydrate availability around selected exercise bouts to augment metabolic adaptations to training is now widely recommended, a contemporary view of the so-called train-low approach based on the totality of the current evidence suggests limited utility for enhancing performance benefits from training. Nonetheless, such studies have focused importance on periodizing carbohydrate intake based on, among other factors, the goal and demand of training or competition. This calls for a much more personalized approach to carbohydrate recommendations that could be further supported through future research and technological innovation (e.g., continuous glucose monitoring). Despite more than a century of investigations into carbohydrate nutrition, exercise metabolism and endurance performance, there are numerous new important discoveries, both from an applied and mechanistic perspective, on the horizon.
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