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Updated: Jul 13, 2026
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Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans
Published on: October 17, 2018
Effects of acute prednisolone intake on substrate utilization during submaximal exercise
A Arlettaz1, H Portier, A-M Lecoq
1LAPSEP, UFR STAPS Orléans, Orléans Cedex 2, France. alexandre.arlettaz@univorleans.fr
International Journal of Sports Medicine
|July 7, 2007
Summary
Acute prednisolone intake alters exercise metabolism. This study found that prednisolone (Pred) reduced carbohydrate oxidation and increased fat oxidation during submaximal exercise in healthy males.
Area of Science:
- Exercise Physiology
- Endocrinology
- Sports Science
Background:
- Glucocorticoids are potent metabolic regulators.
- Understanding their impact on fuel utilization during exercise is crucial for athletes and clinicians.
Purpose of the Study:
- To investigate the effect of acute therapeutic glucocorticoid (prednisolone) intake on substrate utilization (fat and carbohydrate) during submaximal exercise.
- To assess changes in energy expenditure and hormonal responses.
Main Methods:
- Double-blind, randomized, placebo-controlled crossover study.
- Nine healthy recreationally-trained males performed 60-minute submaximal exercise (60% VO2max) after ingesting placebo or 20mg prednisolone.
- Respiratory exchange and blood samples were analyzed.
Main Results:
- Prednisolone intake significantly increased total energy expenditure during exercise.
- Carbohydrate oxidation was lower, and fat oxidation was higher with prednisolone compared to placebo.
- Adrenocorticotropic hormone (ACTH) and Interleukin-6 (IL-6) levels decreased with prednisolone.
Conclusions:
- Acute systemic administration of prednisolone reduces carbohydrate oxidation during submaximal exercise.
- This shift towards fat oxidation may have implications for athletic performance, warranting further investigation in elite athletes.
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Introduction
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Definition
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Purposes
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes