Performance and Psychophysiological Responses to Mental Fatigue in Artistic Swimming

Background: We investigated the effect of mental fatigue (MF) on artistic swimmers’ (AS) physiological and cognitive responses and physical and technical AS performance. Methods: Twelve young female ASs completed a free team routine (FT) involving 4 × 4 min trials separated by a 2 min rest in two sessions a week apart. Pre- and post-FT, athletes performed three “boosts” for vertical displacement and a 50 m maximum effort front crawl swim. Before each session, a 30 min MF test (Stroop condition; SC) or an emotionally neutral video (control condition; CC) were implemented in counterbalanced order. Choice reaction time and central executive function tests were applied before and after the completion of both conditions. Technical performance was evaluated by five official judges. Heart rate was continuously recorded, whilst blood lactate was measured before the start and after the second and fourth FT. Rating of perceived exertion (RPE) was recorded after each FT. Results: Technical performance scores during FT were lower in SC than CC (6.82 ± 0.92 vs. 7.17 ± 0.69, p < 0.001, and d = 0.43). The choice reaction time was decreased by 3.4 ± 9.3% in SC but increased 4.4 ± 8.1% in CC (p < 0.05). Central executive function was no different between conditions despite a medium effect size in SC (d = 0.58). The “boost” height was lower in SC compared to CC (70 ± 5 vs. 72 ± 5 cm, p < 0.05, and d = 0.45). Heart rate, RPE, and 50 m time did not differ between conditions (p > 0.05), but blood lactate was higher in the CC compared to SC (5.3 ± 2.6 vs. 4.6 ± 2.9 mmol/l, p < 0.05, and d = 0.25). Conclusion: Mental fatigue may impair technical performance during FT, primarily via cognitive dysfunction, with reduced glycolytic activation as a potential additional factor.