Feasibility and Effects of Lower-Body Electrical Muscle Stimulation Resistance Training on Body Composition, Muscle Function, Arteriosclerotic Indices, and Autonomic Function in Postmenopausal Women: A Pilot Randomized Controlled Trial
Feasibility and Effects of Lower-Body Electrical Muscle Stimulation Resistance Training on Body Composition, Muscle Function, Arteriosclerotic Indices, and Autonomic Function in Postmenopausal Women: A Pilot Randomized Controlled Trial
This pilot randomized controlled trial evaluates whether combining lower-body electrical muscle stimulation (EMS) with resistance training is feasible and beneficial for physically inactive postmenopausal women, who experience concurrent declines in muscle strength, body composition, arterial elasticity, and cardiac autonomic balance.
Sixteen physically inactive postmenopausal women aged 50-70 years are randomly assigned (1:1) to either (A) supervised resistance training combined with lower-body EMS (applied to 6 muscle groups: lower back, lower abdomen, glutes, quadriceps, hamstrings, and calves) or (B) supervised resistance training alone. Both groups complete twelve 50-minute sessions (consisting of a 10-minute warm-up, 30-minute main exercise, and a 10-minute cool-down) over 6 weeks (twice weekly). Assessments before and after the intervention include body composition, lower-body muscle function, arterial stiffness, and 5-minute heart rate variability.
The primary aim is to determine the feasibility of the protocol(recruitment, retention, session attendance, and intervention dose delivery) to inform a future definitive trial. Preliminary estimates of intervention effects on the measured outcomes are reported as secondary aims.
BACKGROUND AND RATIONALE Postmenopausal women often experience physiological declines in muscle function, body composition, and cardiovascular health. While resistance training is an established countermeasure, maximizing its efficiency and adherence remains a challenge. Applying lower-body electrical muscle stimulation (EMS) during resistance training may enhance physiological adaptations and overall training effectiveness. This study aims to evaluate the feasibility of combining lower-body EMS with resistance training in physically inactive postmenopausal women to inform the design of a future definitive trial.
STUDY DESIGN This is a pilot randomized controlled trial. Participants will be randomly assigned to either an intervention group receiving combined lower-body EMS and resistance training or a control group receiving resistance training alone. Clinical and physiological outcomes will be assessed before and after the intervention period to evaluate preliminary effects.
PRIMARY FEASIBILITY OUTCOMES
The primary objective is to evaluate the feasibility of the study protocol. Feasibility will be determined by assessing several key components, including:
Recruitment: The ability to recruit the target population within the planned timeframe.
Retention: The proportion of participants who complete the study and post-intervention assessments.
Adherence: Participant attendance and compliance with the scheduled exercise sessions.
Intervention Fidelity: The successful delivery of the exercise intensity and EMS protocol as intended.
These components will be evaluated against pre-established progression criteria to determine whether the protocol can proceed to a larger trial or requires modification.
STATISTICAL APPROACH Feasibility outcomes will be summarized primarily using descriptive statistics. For secondary physiological and clinical outcomes, appropriate statistical methods will be utilized to estimate the preliminary effects of the intervention, comparing changes between the groups while adjusting for baseline measurements. Effect sizes and confidence intervals will be calculated to provide preliminary evidence and to assist with sample size calculations for future large-scale trials.
Inclusion Criteria:
Exclusion Criteria: