Cognitive fatigue effects on physical performance: A systematic review and meta-analysis

Area of Science:

• Sports Science
• Cognitive Neuroscience
• Exercise Physiology

Background:

• Cognitive fatigue is theorized to impair physical performance through mechanisms like brain energy depletion or neurotransmitter changes.
• Existing literature questions whether 90 minutes of cognitive activity can significantly deplete these resources.
• The relationship between cognitive fatigue and subsequent physical performance requires further investigation.

Purpose of the Study:

• To systematically review and meta-analyze the evidence on the effect of cognitive fatigue on subsequent physical performance.
• To determine if cognitive fatigue, as induced by tasks up to 90 minutes, has a significant impact on physical capabilities.

Main Methods:

• A systematic literature search and meta-analytic review were conducted.
• Studies comparing physical performance after a cognitive fatigue task versus a control condition were included.
• Statistical analysis included pooled effect size calculation and heterogeneity testing.

Main Results:

• A small but statistically significant pooled effect size (g = -0.27) indicated a negative impact of cognitive fatigue on physical performance.
• However, low heterogeneity (p > 0.10) suggested the observed differences were likely due to random error rather than a consistent effect.
• No evidence of publication bias was found.

Conclusions:

• The findings present a contradiction: a statistically significant effect size exists, yet heterogeneity tests indicate it may not represent a real-world effect.
• The current evidence does not robustly support the claim that cognitive fatigue significantly impairs physical performance.
• Future studies should incorporate neuroscientific measures to objectively confirm the induction of cognitive fatigue.