Mental fatigue might be not so bad for exercise performance after all: a systematic review and bias-sensitive meta-analysis.

Abstract

There is an ongoing debate in the scientific community regarding whether a state of mental fatigue may have a negative effect upon a range of objective and subjective measures of human performance. This issue has attracted attention from several fields, including sport and exercise sciences. It has been proposed that performing a long and demanding cognitive task might lead to a state of mental fatigue, impairing subsequent exercise performance. In the current meta-analysis, we sought to examine the influence of mental fatigue on performance and ratings of perceived exertion (RPE). The analysis yielded small-to-medium effects of mental fatigue on exercise performance, dz = 0.50, and RPE, dz = 0.21. However, it also revealed evidence of publication or reporting biases. A selection model suggests that the bias-corrected estimates might be substantially lower (0.08 and 0.10, respectively) and non-significant. In sum, current evidence does not offer conclusive support for the claim that mental fatigue (induced by long and demanding cognitive tasks) has a negative influence on exercise performance.

Non-local muscle fatigue effects on muscle strength, power, and endurance in healthy individuals: A systematic review and meta-analysis

“…Nevertheless, a deficit in cognitive capacity may influence phenomenological experience more globally and potentially explain NLMF especially during endurance-based tasks [7]. Cognitively fatiguing tasks may lead individuals to perceive a subsequent task to be more effortful, resulting in an earlier cessation of the activity [98][99][100]; though again this finding is not consistent and may be small [101]. Actual fatigue (and indeed effort) is distinct from the perception of fatigue (and perception of effort) [102].…”

Prolonged cognitive activity increases perception of fatigue but does not influence perception of effort, affective valence or performance during subsequent isometric endurance exercise.

“…Holgado et al, 2020;Martin et al, 2016;Silva-Cavalcante et al, 2018;. Though recent meta-analyses, adopting a broad inclusion criteria , extoll a small-to-moderate negative effect of mental fatigue on subsequent physical performance (Brown et al, 2020;Giboin & Wolff, 2019), others have raised concerns regarding conclusions drawn on the impact of mental fatigue on physical performance (Holgado et al, 2019;McMorris et al, 2018). The divergent conclusions offered by recent meta-analyses may be attributable to several methodological differences, including inclusion criteria (e.g.…”

“…However, concerns remain regarding the veracity of the effect of mental fatigue on subsequent endurance performance and the putative causative mechanisms (Holgado et al, 2019;McMorris et al, 2018). For example, a large sample replication study from Holgado et al (2020) failed to replicate the negative effects of mental fatigue reported in the seminal work of Marcora et al (2009).…”

“…In keeping with recent calls(Pattyn et al, 2018), increasing collation of evidence across disparate research fields have been incorporated by two recent meta-analyses assessing the effect of mental fatigue on physical performance(Brown et al, 2020;Giboin & Wolff, 2019). In the case of prior cognitive activity and its impact on physical performance, this includes the literature pertaining to "mental fatigue" in the exercise sciences and "egodepletion" in cognitive psychology.3 Cognitive tasks >30 minutes are often demarcated as the only tasks suitable when studying "mental fatigue"(Holgado et al, 2019;, since this has been shown to be the duration at which vigilance decrements occur(Nuechterlein et al, 1983) and subjective reports of mental fatigue increase(Smith et al., 2016). This definition has recently received some criticism, offering the possibility that a large body of work on the topic may have been neglected by the adopted of such inclusion criteria(Brown et al, 2020).…”

A primer on the role of boredom in self-controlled sports and exercise behavior

“…However, the magnitude of performance impairment is not robustly linked to the duration of the prior self-control task 5 , which conflicts with the theoretical proposition that the magnitude of the performance decrement should scale linearly with the duration of the prior self-control task 9 . In addition, a recent bias-sensitive meta-analysis of the literature suggests that initial estimates of the effects of prior selfcontrol on subsequent sports performance might be smaller than initially assumed 14 . This inconsistent body of literature limits our understanding of the relationship between self-control and sports performance.…”