Is Electrical Muscle Stimulation an Alternative to Exercise?

Abstract

Recent studies suggest that electrical muscle stimulation （EMS） has the potential to be an alternative modality to voluntary exercise. However, the effects of EMS on human body are not well understood. Thus, the purpose of this study was to examine the effects of EMS training on quadriceps muscle hypertrophy and strength, vascular endothelial function, autonomic nervous system function, and cognitive function. Methods: Thirty heathy male participants were divided into EMS training, resistance exercise training, and control groups. In the EMS training group, the participants performed EMS three times per week for 8 weeks. In the resistance exercise training group performed leg-press three times per week for 8 weeks. Cross-sectional area （CSA） of the quadriceps muscle was assessed at mid-thigh （50% of the femur） and distal （70%） regions using magnetic resonance imaging. At mid-thigh and distal regions, muscle CSA increased after both EMS and resistance exercise trainings. Isometric knee extension strength increased in the EMS group. The EMS training also increased vascular endothelial function. Both training did not affect autonomic nervous system activation and cognitive function. These results indicate that EMS potentially induces muscle hypertrophy, increases muscle strength, and improves vascular endothelial function. The present findings suggest that EMS can be an alternative to voluntary exercise.