An examination of the effect of mental fatigue on grip strength (2010)

Undergraduate: Jason Gonzalez

Faculty Advisor: Kristin Ondrak
Department: Exercise & Sport Science

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Mental fatigue has been shown to effect physical endurance, skill, and subjective perceptions of physical exertion. A 2009 study (Marcora et al.) examined the effects of mental fatigue on endurance and found a negative relationship, such that increases in mental stress and fatigue decreased endurance. However, little is known about the effects of mental fatigue on strength and this study examined these relationships. Two groups of 15 recreationally active, male students, aged 18 to 22, were tested for maximum grip strength before and after one of two Stroop color-word interference tasks (incongruent task or monochromatic task). A positive affect negative affect schedules (PANAS) were given immediately after each grip strength test to observe for changes in mental fatigue. We hypothesized that grip strength would decrease, positive affect would decrease, and negative affect would increase more following a mentally fatiguing activity (incongruent task) compared to the control activity (monochromatic test). Grip strength decreased in both groups but failed to reach statistical significance between groups (p = 0.833). Positive affect decreased in both groups (p = 0.307) and negative affect did not change between groups (p = 0.929). Therefore, the results of this study showed that mental fatigue has no observable effect on grip strength.