The Effect of a Mental Task Versus Unilateral Physical Fatigue on Non-Local Muscle Fatigue in Recreationally Active Young Adults

Non-local muscle fatigue (NLMF) has been attributed to both physical and mental fatigue. The purpose of this study was investigate the effects exertion versus unilateral on NLMF. Sixteen recreationally active participants completed a task (2-sets 100-s knee extension (KE) maximal voluntary isometric contractions (MVIC) with dominant leg 40-s recovery between sets, (4-minute Stroop task), control condition. Before after each condition, blood lactate collected, contralateral 5-s KE, flexion (KF) bilateral lateral trunk flexors MVIC (measure stability strength) performed. Following post-test MVICs, performed 12 non-dominant KE MVICs work-to-rest ratio 5/10-s. Electromyography monitored during MVICs. Neither 4-minute test or intervention adversely affected forces EMG activity single repetition Although KF index hamstrings were not impaired by interventions, there significant interaction (p = 0.001) small magnitude (d 0.42) decrease in force following intervention, albeit no change EMG. This deficit may be related 0.046, d 2.6) external obliques 0.048, 0.57) activation affecting stability. In conclusion, did impair repeated activity. are accord heterogenous findings common literature.