Physical fatigue exacerbates the negative effects of mental fatigue on soccer performance in practitioners

Soccer is mentally as well as physically fatiguing. Negative effects of isolated mental fatigue on soccer performance have been reported, however, it does not appear isolated in soccer. This study compared the effects of baseline, mental fatigue and combined mental and physical fatigue on soccer performance. Voluntarily, 18 male soccer practitioners (23.61 ± 4.12y) participated in six randomized and crossover sessions– two non-induced fatigue baseline (30 min. documentary), 2 isolated mental fatigue (30 min. Incongruent Stroop) and 2 combined physical and mental fatigue (30 min. Incongruent Stroop while cycling at 80-85% of the theoretical Maximum Heart Rate). The Visual Analogue Scale pre- and post- fatiguing protocol for mental fatigue, and the Questionnaire to Quantify Mental Load in Sports Team for mental load post-fatiguing protocol were collected. The Loughborough shooting and passing test were performed post- fatiguing protocols. Results revealed the combined protocol as the most mentally loading and fatiguing, showing significant differences when compared with isolated mental fatigue and baseline (p<.001). Isolated mental fatigue was significantly more mentally loading (p<.001) and fatiguing (p<.001) that baseline. Significant impairments on soccer performance were observed after isolated mental fatigue and combined protocols in comparison with baseline (p<.001). However, these impairments were significantly higher after combined than isolated mental fatigue (p<.043). In conclusion, the presence of physical fatigue combined with mental fatigue exacerbates the negative effects that isolated mental fatigue causes on soccer performance.