Effects of mental fatigue on soccer-specific performance in young players.

Subjective ratings of mental fatigue were higher after the Stroop task compared to the control in U14, U16 and U18 in both parts. Mental fatigue significantly reduced Yo-Yo IR1 distance, alongside an increase in heart rate and ratings of perceived exertion, and this effect was moderated by age as older players showed greater declines in performance. Soccer-specific technical performance was negatively affected by mental fatigue condition only in U18 in the LSPT..