title: Does mental exertion alter maximal muscle activation?
abstract: Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 min each: (i) high mental exertion (incongruent Stroop task), (ii) moderate mental exertion (congruent Stroop task), (iii) low mental exertion (watching a movie). In each condition, mental exertion was combined with 10 intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 min). Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France.
authors.forename: Vianney
authors.initials: V
authors.lastname: Rozand
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France ; Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway Chatham Maritime, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Pageaux
authors.affiliation: Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway Chatham Maritime, UK.
authors.forename: Samuele M
authors.initials: SM
authors.lastname: Marcora
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Papaxanthis
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France.
authors.forename: Romuald
authors.initials: R
authors.lastname: Lepers
keywords: Stroop task; central fatigue; knee extensors; mental fatigue; motivation; neuromuscular fatigue