Mental fatigue does not alter performance or neuromuscular fatigue development during self-paced exercise in recreationally trained cyclists

• DOI: 10.1007/s00421-018-3974-0
• Publication Date: 2018-08-28T06:47:03Z
• Authors: Marcos David Silv...; Patrícia Guimarae...; Rafael de Almeida...; Renata Gonçalves ...; Daniel Boari Coelho; Adriano Eduardo L...; Romulo Bertuzzi
• Keywords: Adult; Male; Electromyography; Athletic Performance; Mental Fatigue; Bicycling; 03 medical and health sciences; Cognition; 0302 clinical medicine; Muscle Fatigue; Physical Endurance; Humans; Muscle, Skeletal; Exercise

The purpose of this study was to investigate the effects of mental fatigue, characterized by a subjective feeling of tiredness, on the development of neuromuscular fatigue during a 4-km cycling time trial (4-km TT).Eight recreationally trained male cyclists performed a 4-km TT after either performing a prolonged cognitive task (mental fatigue) or after viewing emotionally neutral documentaries (control). The neuromuscular function of the knee extensors was assessed using electrical nerve stimulation at baseline, before (pre-TT), and after (post-TT) the 4-km TT. Rating of perceived exertion (RPE) and physiological variables were periodically measured during 4-km TT.Subjective ratings of fatigue increased significantly only after a prolonged cognitive task (P = 0.022). Neuromuscular function at baseline was similar between conditions and remained unchanged at pre-TT. Time to complete the 4-km TT was similar between control (376 ± 27 s) and mental fatigue (376 ± 26 s). There was no significant difference between conditions for RPE, [Formula: see text], [Formula: see text], and HR throughout the exercise. The 4-km TT-induced similar decrease (from baseline to post-TT) in maximal voluntary contraction (mental fatigue - 11 ± 10%, control - 16 ± 12%), twitch force (mental fatigue - 26 ± 16%, control - 24 ± 17%), and voluntary activation (mental fatigue - 5 ± 7%, control - 3 ± 2%) for both conditions.Mental fatigue induced by prolonged cognitive task does not impair performance nor alter the degree of central and peripheral fatigue development during self-paced exercise in recreationally trained cyclists.