Effects of voluntary exercise and electrical muscle stimulation on reaction time in the Go/No-Go task.

Introduction: Acute exercise improves cognitive performance. However, it remains unclear what triggers cognitive improvement. Electrical muscle stimulation (EMS) facilitates the examination of physiological changes derived from peripheral muscle contraction during exercise. Thus, we compared the effects of EMS and voluntary exercise at low- or moderate-intensity on reaction time (RT) in a cognitive task to understand the contribution of central and peripheral physiological factors to RT improvement.
Methods: Twenty-four young, healthy male participants performed a Go/No-Go task before and after EMS/exercise. In the EMS condition, EMS was applied to the lower limb muscles. In the low-intensity exercise condition, the participants cycled an ergometer while maintaining their heart rate (HR) at the similar level during EMS. In the moderate-intensity exercise condition, exercise intensity corresponded to ratings of perceived exertion of 13/20. The natural log-transformed root mean square of successive differences between adjacent inter-beat (R-R) intervals (LnRMSSD), which predominantly reflects parasympathetic HR modulation, was calculated before and during EMS/exercise.
Results: RT improved following moderate-intensity exercise (p = 0.002, Cohen' d = 0.694), but not following EMS (p = 0.107, Cohen' d = 0.342) and low-intensity exercise (p = 0.076, Cohen' d = 0.380). Repeated measures correlation analysis revealed that RT was correlated with LnRMSSD (Rrm(23) = 0.599, p = 0.002) in the moderate-intensity exercise condition.
Conclusion: These findings suggest that the amount of central neural activity and exercise pressor reflex may be crucial for RT improvement. RT improvement following moderate-intensity exercise may, at least partly, be associated with enhanced sympathetic nervous system activity.
Competing Interests: Declarations Conflict of interest The authors declare that there is no conflict of interest. Ethics approval This study was approved by the University of Electro-Communications’ Human Ethics Committee (No: 19003). The study conformed to the standards set by the latest revision of the Declaration of Helsinki, except for registration in the database. Consent to participate Informed consent was obtained from all individual participants included in the study.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)