Mental fatigue impairs physical performance in young swimmers

Abstract

Purpose: This study aimed to investigate the impact of mental fatigue on heart rate variability (HRV), subjective measures of fatigue, and swimming performance in young athletes. Method: Sixteen swimmers (15.45 ± 0.51 years old, 7.35 ± 2.20 years of swimming experience) performed a 1500-m time trial on two occasions separated by an interval of at least 72 hours. The 1500-m swimming was preceded by a 30-min treatment that consisted of performing the Stroop Color-Word Test to induce mental fatigue (experimental trial), or watching an emotionally neutral video (control trial). Results: Participants reported higher ratings of mental fatigue and mental effort following the Stroop Test when compared to the control trial, but no differences in motivation were observed. The induction of mental fatigue impaired swimming performance, as evidenced by a slower performance (1.2%) to complete the 1500-m swimming trial. No inter-trial differences were identified for Rates of Perceived Exertion during the swimming test or in HRV after the Stroop and swimming tests. Conclusion: The results suggest that induction of mental fatigue impairs 1500-m swimming performance without changing HRV.