The effect of a single bout of exercise on energy and fatigue states: a systematic review and meta-analysis

• Published in: Fatigue (Abingdon, Eng.) Vol. 1; no. 4; pp. 223 - 242
• Main Authors: Loy, Bryan D., O'Connor, Patrick J., Dishman, Rodney K.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01-10-2013
• Subjects: acute exercise; alertness; energy; fatigue; mood; symptoms; vigor
• ISSN: 2164-1846; 2164-1862
• DOI: 10.1080/21641846.2013.843266

Background: Studies examining acute exercise effects on energy and fatigue levels have not been quantitatively summarized. Purpose: To estimate the population effects of a single bout of exercise on energy and fatigue states and examine potential moderators. Methods: Google Scholar and MEDLINE were searched systematically for published studies that measured changes in energy and fatigue after acute exercise. Meta-analytic techniques were used to analyze 58 energy effects and 58 fatigue effects from the same 16 studies involving 678 participants. Most studies involved 21-40 minutes of moderate-intensity aerobic-type exercise. Result: The homogeneous mean effect for energy was Δ = 0.47 (95% confidence interval [CI] = 0.39, 0.56). The heterogeneous mean effect for fatigue was Δ = 0.03 (95% CI = −0.08, 0.13). The fatigue effect was moderated by a three-way interaction between change in feelings of energy, exercise intensity, and exercise duration. Conclusion: Acute exercise enhances feelings of energy. Decreases in fatigue occur only when post-exercise increases in energy are at least moderately large after low-to-moderate intensity exercise lasting longer than 20 minutes. Future research should focus on short-duration (<15 minutes), vigorous-intensity exercise and long-duration (>40 minutes) exercise in non-student groups.