Acute Effects of Whole-Body Electromyostimulation Versus High-Intensity Resistance Training on Markers of Bone Turnover in Young Females—A Randomized Controlled Cross-Over Trial

The present study aimed to determine the acute effects of high-intensity dynamic resistance training (HI-DRT) and whole-body electromyostimulation (WB-EMS) on markers of bone formation and resorption in young healthy women. Using a crossover design, 17 students of dentistry (26.5 ± 4.0 years, 21.5 ± 2.5 kg/m2) were randomly assigned to begin either with HI-DRT (five exercises, three sets to repetition maximum) or 20 min of non-superimposed, low-frequency (85 Hz), intermitted (6 s impulse/4 s impulse break) WB-EMS. The study outcome parameters were total Procollagen Type-1 N-Terminal Propeptide (P1NP) and Type-I Collagen Cross-Linked C-Telopeptide (CTX), which were sampled immediately prior to and 15 min post intervention. ANCOVA was applied to determine the main effects, i.e., differences in pre–post changes in CTX and P1NP between the interventions. No participant was lost to follow-up or reported adverse effects related to the exercises. Briefly, we observed significant differences (p = 0.019, d′ = 1.19) for changes in P1NP that were maintained in the HI-DRT (p = 0.446) and decreased in the WB-EMS group (p = 0.002). In contrast, we did not observe differences for HI-DRT- vs. WB-EMS-induced CTX changes (p = 0.509; d′ = 0.134). In summary, while HI-DRT provides significantly more favorable effects on bone formation markers compared to WB-EMS, the clinical significance of this finding in predicting the general effectiveness of an exercise protocol on bone strength remains to be determined. (Clinical trials.gov; registration date: 2025-02-06; ID: NCT06813092.)