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Maximal Fat Oxidation Rates in an Athletic Population.
Rebecca K Randell1, Ian Rollo, Timothy J Roberts
11The Gatorade Sports Science Institute, Global Nutrition R&D, PepsiCo, Leicester, UNITED KINGDOM; and 2School of Sports Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.
Medicine and Science in Sports and Exercise
|September 1, 2016
Summary
Maximal fat oxidation (MFO) rates vary widely in athletes, influenced by sport, sex, and fitness. While body composition and fitness explain some MFO variance, over half remains unexplained, highlighting individual differences in fuel utilization.
Area of Science:
- Exercise Physiology
- Sports Science
- Metabolic Research
Background:
- Maximal fat oxidation (MFO) is crucial for endurance performance.
- Understanding MFO in athletes is key for optimizing training and nutrition.
- Significant individual variability in MFO exists, necessitating further investigation.
Purpose of the Study:
- To characterize maximal fat oxidation (MFO) rates in a large cohort of athletes.
- To investigate factors influencing MFO, including sport, sex, body composition, and fitness.
- To identify the exercise intensity at which MFO occurs (FATMAX).
Main Methods:
- Indirect calorimetry was used to measure fat oxidation rates during graded exercise tests.
- 1121 athletes from diverse sports and competitive levels participated.
- Participants were tested in a fasted state (≥5 hours).
Main Results:
- Average MFO was 0.59 ± 0.18 g/min, with substantial individual variation.
- MFO occurred at an average intensity of 49.3% V˙O2max.
- Male athletes had higher absolute MFO, while females had higher MFO relative to fat-free mass (FFM).
- Soccer players exhibited the highest MFO/FFM, while American Football players had the lowest.
Conclusions:
- MFO and FATMAX demonstrate significant inter- and intra-sport variability.
- Body composition and fitness status partially explain MFO variance, but over 50% remains unaccounted for.
- Individual differences in metabolic responses to exercise are substantial in athletes.
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