The Effect Of A Whole-Body Electrical Muscle Stimulation (Wb-Ems) Session On Affective Valence And Arousal In Healthy And Physically Active Adults

Originally used in therapeutic and rehabilitation settings, WB-EMS is now widely incorporated into gyms and wellness centers, primarily associated with increases in strength and muscle hypertrophy. However, its effects on affective responses and pleasure during training remain uncertain. PURPOSE: To evaluate the impact of a WB-EMS session on affective valence and arousal in healthy, physically active adults. METHODS: Eight physically active volunteers (28.3 ± 8.9 years, 1.7 ± 0.1 m, and 72.1 ± 9.1 kg), both male and female, participated in two randomized training sessions, spaced seven days apart: EXPERIMENTAL (WB-EMS: bodyweight exercises and elastic bands + WB-EMS) and CONTROL (CON: exercises with bodyweight and elastic bands without WB-EMS). Each session included a 1-minute warm-up (running in place) and a series of exercises (push-up, squat, elbow extension with elastic band, sit-up, rowing with elastic band, lunge, elbow flexion with elastic band, and lateral raise with elastic band). Two sets of eight repetitions were completed in a circuit format. In the WB-EMS condition, an electromyostimulation suit (XBody®, Dorsten, Nordrhein-Westfalen, Germany) released a bipolar electrical current (frequency: 85 Hz, pulse amplitude: 350 μs) with 4 seconds of stimulation and 2 seconds of recovery. After each exercise set, affective valence (Feeling Scale-FS), arousal (Felt Arousal Scale-FAS), and rate of perceived exertion (RPE 0-10) were measured. Data analysis involved the Shapiro-Wilk test for Gaussian distribution and paired t-tests or Wilcoxon signed-rank tests to compare conditions. Effect sizes (Cohen's d) were calculated, with an alpha level of 0.05 for statistical significance. RESULTS: Significant differences were found in RPE (WB-EMS: 7.27 ± 1.79 vs. CON: 4.30 ± 2.16; d = 0.25; p = 0.02), affective valence (WB-EMS: 4.19 ± 1.30 vs. CON: 3.85 ± 1.39; d = 0.25; p = 0.03), and arousal (WB-EMS: 4.95 ± 1.27 vs. CON: 3.75 ± 1.52; d = 0.63; p = 0.01), with WB-EMS showing higher values than CON. CONCLUSIONS: Despite a higher perceived exertion (RPE), WB-EMS led to increased affective valence and arousal among participants.