Related Experiment Video
Updated: Sep 25, 2025
07:26
Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans
Published on: October 17, 2018
20.7K
A Comparison of Substrate Utilization Profiles During Maximal and Submaximal Exercise Tests in Athletes
Rohit Ramadoss1, Joseph R Stanzione2, Stella Lucia Volpe1
1Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States.
Frontiers in Psychology
|April 25, 2022
Summary
Exercise intensity and body composition significantly impact fuel utilization during exercise. Maximal efforts show a later shift to glucose predominance, and higher body fat percentage predicts greater fat burning during intense exercise.
Area of Science:
- Exercise Physiology
- Metabolic Adaptations
- Sports Science
Background:
- Exercise relies on lipids and glucose for energy.
- Substrate utilization patterns vary based on exercise conditions.
- Factors influencing substrate utilization require further investigation.
Purpose of the Study:
- To compare substrate utilization profiles during maximal and submaximal exercise tests.
- To determine the influence of body composition on substrate utilization during exercise.
- To analyze the relationship between exercise intensity and fuel source preference.
Main Methods:
- 27 male athletes underwent body composition analysis via bioelectrical impedance.
- Maximal and submaximal graded exercise tests were conducted on a treadmill.
- A novel submaximal protocol was employed to assess substrate utilization.
Main Results:
- The crossover point (shift to glucose predominance) occurred at a higher VO2max percentage during maximal (76%) vs. submaximal (58%) tests.
- Percent body fat significantly predicted VO2max at the crossover point during maximal exercise (R²=0.245).
- Body composition did not significantly affect VO2max at the crossover point during submaximal exercise.
Conclusions:
- Exercise intensity significantly influences the shift in substrate utilization.
- Body composition, specifically percent body fat, is a key predictor of fuel use during maximal exercise.
- Higher body fat percentage in athletes may correlate with increased lipid oxidation during high-intensity exercise.
