Acute effects of whole body electro stimulation during a single maximal strength training session

Abstract

INTRODUCTION: Whole body electrostimulation (WB-EMS) devices have been used in both performance and health related training programs and the scientific literature has shown that it can be an effective tool to improve training adaptations. However, WB-EMS efficiency is being questioned nowadays. Further, it has been suggested that WB-EMS could lead to excessive physical strain and health problems due to the lack of a scientific based specific WB-EMS training method and professional formation of coaches. The aim of this study was to assess the training effects of two protocols of WB-EMS during a single maximal strength session. METHODS: Eleven subjects with previous experience in strength training of 3-5 days/week during, at least, the past 3 years participated in the study. They performed a familiarization trial with the WB-EMS device and a 1RM test based on mean propulsive velocity analysis for bench press and full-squat to stablish their 90%1RM load. Then, subjects performed three maximal strength sessions consisting of 5 sets of 5 repetitions with 3 minutes of rest between sets of bench press and full-squat using different protocols: WB-EMS with continuous stimulus (85 Hz, 250/350 µs ; Cont-EMS), WB-EMS with stimulus coordinate with the movement concentric phase (85 Hz, 250/350 µs, 1 s strain to 2 s rest; Coord-EMS) and a session without WB-EMS (No-EMS). RESULTS: During sessions, heart rate, peripheral capillary oxygen saturation and perceived exertion showed no significant differences. Also, no differences were found among trials in heart rate variability, squat jump, countermovement jump, Abalakov jump, handgrip and frequency of striking for 5 seconds. Blood lactate (BL) was significantly increased only after Coord-EMS (1.8 ± 2.2 mmol/L: p<0.05). Creatine kinase increased significantly immediately after Cont-EMS (12.3 ± 16.7 IU/L) and No-EMS (30.6 ± 47.0 IU/L; p<0.05), but not after Coord-EMS (4.5 ± 39.5 IU/L). No differences were found in CK levels 24 after training sessions. CONCLUSION: According to these data, strength training with WB-EMS device did not mean risk for athlete´s health, in fact, the greatest increased in CK level after training was produced after No-EMS training. In the other hand, BL was higher after Coord-EMS, this could mean that coordinating the electrostimulation with the movement concentric phase provokes a higher impact training due to larger anaerobic effect.