DescriptionINTRODUCTION: Mental fatigue, a psychobiological state that is induced when engaging in prolonged cognitive activity, affects both cognitive as well as physical performance. However, the significance and magnitude of these effects has recently been questioned. One of the underlying reasons could be the interindividual differences that are present in mental fatigue-effects. However, it’s not known yet whether these interindividual differences are trait or state-related, or which internal and/or external factors mediate these interindividual differences. The aim of this systematic review and meta-regression was to give an overview of interindividual differences in the effects of mental fatigue on physical performance, and possible internal factors influencing this effect. METHODS: Pubmed, Web of Science, SPORTDiscus and PsycINFO were searched for studies detailing the effect of mental fatigue on dynamic maximal whole body endurance performance. Studies needed to feature healthy participants with the inclusion of at least one internal factor in participants’ characteristics, and were required to include at least one manipulation check. The Cochrane crossover risk of bias tool was used to assess risk of bias. The meta-analysis and regression itself were conducted in R. RESULTS: 29 studies were selected for inclusion, with 24 studies eventually added to the overall random-effects meta-analysis (with 34 distinct effects) based on the successful induction of mental fatigue. This meta-analysis showed a small but significant effect of mental fatigue on endurance performance (g = - 0.31, 95% CI [-0.44; -0.17], t = -4.83, p < 0.001). The multiple meta-regression analysis (incorporating 11 effects) showed a significant influence of physical fitness level on mental fatigue-effects (estimate = 0.18, SE = 0.06, t = 2.84, p = 0.0296). However, this effect was only present when incorporated within the model together with sex ratio, mean age and body mass index. CONCLUSION: The present review confirms findings of the overall literature regarding the mediating influence of physical fitness level on the negative effects of mental fatigue on endurance performance. However, this influence is only apparent when different individual factors, such as sex, are taken into account. Moreover, multiple limitations still undermine these conclusions, from the overall underreporting of different participant characteristics to significant publication bias. An overall experimental study incorporating multiple different internal factors is therefore necessary to draw a definitive conclusion on this subject.
|Period||31 Aug 2022|
|Event title||ECSS 2022|
|Degree of Recognition||International|