Comparing the effects of 25-minute electrical muscle stimulation vs. 90-minute full-body resistance training on body composition and strength: A 20-week intervention

Abstract

Objectives

Electromyostimulation (EMS) and traditional resistance training (TradRT) are widely used methods for improving muscle strength and body composition. However, comparative studies employing a multi-week longitudinal design remain limited. This study aimed to investigate the effects of 20 weeks of EMS vs. TradRT on body composition and strength performance in physically active adults.

Methods

Forty-six participants were randomly assigned to either the EMS group (n = 22) or the TradRT group (n = 24). The EMS group performed twice-weekly, 25-min whole-body EMS sessions, while the TradRT group completed twice-weekly, 90-min full-body resistance training sessions.

Results

Assessments of body weight, body mass index (BMI), fat percentage, and maximal strength were conducted at baseline, 10 weeks, and 20 weeks. A significant time effect was observed for all variables (p < 0.001), indicating improvements in both groups. However, group × time interactions revealed distinct adaptation patterns. The TradRT group exhibited greater reductions in body fat percentage and superior strength gains in bench press, leg press, shoulder press, and triceps pushdown, and abdominal strength. Conversely, the EMS group showed greater reductions in body weight and BMI. No significant interaction effect was observed for biceps curl strength. Both EMS and TradRT were effective in improving strength and body composition, but TradRT led to greater strength development and fat reduction, while EMS was more effective for weight and BMI reduction.

Conclusions

These findings suggest that EMS may serve as a viable alternative for individuals unable to engage in high-load resistance training, whereas TradRT remains superior for maximizing strength and fat loss.

1. Introduction

Resistance training is widely recognized as a fundamental method for improving body composition and muscular strength.1, 2, 3 It plays a crucial role in optimizing physical performance, enhancing muscle function, and supporting overall health.^4,5 Key indicators of body composition, such as body mass index (BMI) and fat percentage, are strongly associated with metabolic health and the risk of chronic diseases.^6,7 Additionally, strength performance, measured through exercises like bench press, leg press, and other resistance-based movements, reflects an individual's muscular capacity and functional ability.^3,8 Numerous studies have demonstrated that structured resistance training programs contribute to increased muscle mass, reduced fat percentage, and enhanced strength levels in both trained athletes and untrained individuals.^9,10 Given these benefits, resistance training remains a cornerstone of physical conditioning, rehabilitation, and athletic development.

Electrical muscle stimulation (EMS) and traditional resistance training (TradRT) are two distinct approaches used to enhance muscle strength and improve body composition. EMS involves the application of electrical impulses that directly stimulate muscle contractions, mimicking voluntary resistance exercises.^11,12 This method is typically performed in short, high-intensity sessions, often lasting around 25 min, making it an efficient alternative for individuals with time constraints.^13,14 Research suggests that EMS can effectively enhance muscle activation, promote fat loss, and improve muscular endurance through high-frequency stimulation.^15,16 In contrast, TradRT consists of exercises performed with free weights, machines, or body weight, applying progressive overload to induce muscular adaptations. These workouts generally last longer, around 90 min, and have been shown to significantly increase muscle hypertrophy, maximal strength, and overall physical performance.^3,17 While both training methods aim to improve strength and body composition, their distinct physiological mechanisms may lead to different long-term adaptations.

Although both EMS and traditional resistance training have been widely studied, research employing multi-week longitudinal designs to evaluate their sustained effects remains limited. Most EMS studies have focused on short-term interventions, typically ranging from a few weeks to three months, with mixed findings on its effectiveness compared to conventional resistance training.^11,15 While EMS has been shown to enhance muscle activation and strength in the short term, its ability to sustain improvements over extended periods is still debated. Conversely, extended-duration trials on resistance training have consistently demonstrated progressive gains in muscle hypertrophy, strength, and overall functional performance.^3,4,17 However, direct comparisons between EMS and TradRT in a controlled, multi-week intervention context are scarce. Moreover, the potential differences in how these methods influence key physiological adaptations—such as fat reduction, muscle hypertrophy, and strength retention—over time remain unclear. Addressing this gap is crucial to understanding whether EMS can serve as an effective alternative to traditional training or if its benefits are primarily limited to short-term applications.

Given the existing research gaps, this study aims to compare the effects of 25-min EMS training and 90-min TradRT on body composition and strength performance over a 20-week period. By assessing changes at baseline, 10 weeks, and 20 weeks, this study seeks to determine whether EMS can produce similar or superior adaptations compared to TradRT in terms of muscle strength and body composition improvements. The primary hypothesis is that both training modalities will lead to significant improvements in body composition and strength performance over time. However, it is expected that EMS may offer time-efficient improvements, whereas TradRT may be more advantageous for progressive strength development, particularly when applied over longer durations. This study will contribute to the ongoing discussion on the efficiency and effectiveness of EMS as a potential alternative to traditional resistance training, providing valuable insights for athletes, fitness professionals, and individuals seeking time-efficient training strategies.

2. Methods

2.1. Participants

A priori power analysis was conducted using G∗Power 3.1.9.4 to determine the required sample size for this study. The analysis was based on an ANOVA with repeated measures (within-between interaction), which is appropriate for examining the effects of EMS and TradRT across three time points (baseline, 10 weeks, and 20 weeks).

2.1.1. Sample size calculation

The effect size (f) was derived from pooled effect size values reported in Rodrigues-Santana et al.¹⁸ and Kemmler et al.¹¹ The calculations included:

• •Body Fat.¹⁸: Cohen's d = 0.40, f = 0.283
• •Leg Strength¹⁸: Cohen's d = 0.98, f = 0.693
• •Trunk Strength¹⁸: Cohen's d = 1.08, f = 0.764
• •Body Fat¹¹: Cohen's d = 0.38, f = 0.269
• •Strength¹¹: Cohen's d = 0.54, f = 0.382

The estimated sample size varied depending on the effect size used in the power analysis. Specifically, the smallest sample size requirement was 8 participants when using an effect size of f = 0.764, while the largest required sample size was 38 participants for an effect size of f = 0.269. These effect sizes were derived from pooled estimates of body fat, leg strength, and trunk strength outcomes reported in Rodrigues-Santana et al.¹⁸ and Kemmler et al. (2021).¹¹ Additionally, to ensure that the study had sufficient statistical power (1−β = 0.95) while maintaining a standard significance level (α = 0.05), a conservative medium effect size (f = 0.25) was selected, as it falls within the range of previously reported values. Based on these parameters, the G∗Power analysis determined that a total sample size of 44 participants (22 per group) would be required to achieve adequate power for detecting significant differences over time. The key input parameters for the power analysis included an effect size of 0.25, an α error probability of 0.05, and a statistical power of 0.95. The analysis was conducted for two independent groups (EMS and TradRT), with three measurement time points (baseline, 10 weeks, and 20 weeks). Additionally, a correlation of 0.5 was assumed among repeated measures, and a nonsphericity correction factor (ε) of 1 was applied to account for variance assumptions in the repeated-measures design.

Given the intensive nature of the training intervention and the 20-week study duration, a 20 % increase in sample size was applied to account for potential dropout, leading to an initial recruitment target of 52 participants. However, six participants did not complete the study (four from the TradRT group and two from the EMS group), resulting in a final sample size of 46 participants (EMS: n = 22, TradRT: n = 24). This final sample size meets or exceeds all previously calculated estimates, ensuring sufficient statistical power (actual power = 0.96) to detect significant within-group and between-group differences over time while maintaining the study's robustness and validity.

2.1.2. Group allocation and participant characteristics

Participants were randomly assigned to two groups using a stratified allocation method based on body fat percentage to ensure an even distribution of body composition characteristics between groups. The entire sample was ranked by body fat percentage, and participants were alternately assigned to the EMS group or the TradRT group in an alternating sequence to minimize baseline differences. The EMS group consisted of 22 participants, including 17 males and 7 females, with an average age of 28.2 ± 7.4 years, an average height of 171.2 ± 8.2 cm, and a baseline weight of 85.4 ± 19.9 kg. The TradRT group included 24 participants, comprising 15 males and 7 females, with an average age of 29.9 ± 6.4 years, an average height of 173.0 ± 8.7 cm, and a baseline weight of 84.3 ± 15.3 kg.

All participants were healthy, recreationally active adults aged 18–40 years, recruited from local fitness centers and university sports programs, engaging in moderate unstructured physical activity (e.g., recreational sports or walking, 2–3 h/week) but not structured resistance training in the prior 6 months. Additionally, they had to have no history of neuromuscular disorders, cardiovascular disease, or orthopedic injuries. Participants were excluded if they had used anabolic steroids or other performance-enhancing drugs, were involved in other structured strength training programs during the study period, or failed to comply with the training protocol, including missing more than 10 % of the training sessions.

2.2. Study design

This study was designed as a parallel-group, randomized controlled trial, comparing the effects of EMS training and TradRT on body composition and strength performance over a 20-week period. Participants were stratified based on body fat percentage before being randomly assigned to either the EMS group or the TradRT group to ensure a balanced distribution of baseline characteristics between groups. Each group followed a structured 20-week training program, completing a total of 40 training sessions (twice per week). Participants who missed a scheduled session were given the opportunity to complete it on the following day, ensuring adherence to the protocol. However, a minimum recovery period of 48 h between training sessions was maintained to prevent overtraining and ensure optimal adaptation. The EMS training sessions lasted 25 min, whereas the TradRT sessions lasted 90 min. Despite differences in session duration, both training protocols were designed to stimulate muscular adaptation through different mechanisms. Adherence to the training program was high, with participants attending over 90 % of the scheduled sessions.

Participants were instructed to maintain their habitual dietary patterns throughout the 20-week intervention to reflect real-world applicability and reduce the burden of strict dietary control. To monitor potential dietary influences on body composition and strength outcomes, participants completed a simplified 3-day food diary (two weekdays and one weekend day) at baseline, 10 weeks, and 20 weeks. These diaries captured approximate caloric intake and macronutrient distribution (carbohydrates, proteins, fats) based on self-reported portion sizes and meal frequency, without imposing specific caloric or nutritional targets. Significant deviations in caloric intake (defined as >20 % change from baseline) were flagged, and participants received a verbal warning to stabilize their intake. A second instance of such deviation resulted in exclusion from the study to minimize confounding effects. Dietary data were analyzed descriptively to contextualize training-induced adaptations, acknowledging that precise control was not feasible within the study's naturalistic design.

2.3. Training protocols

2.3.1. EMS training protocol

The EMS training protocol was implemented as a 25-min session conducted twice weekly over a 20-week period, designed to enhance muscle strength and body composition through a structured progression (Table 1). The protocol was developed based on established EMS research^11,19,20 and was supervised by certified trainers to ensure safety, effectiveness, and consistency. A CE-certified Compex Sport Elite EMS device was utilized, delivering biphasic symmetrical rectangular pulses through 10 × 5 cm self-adhesive electrodes positioned bilaterally over the motor points of targeted muscles. Electrodes were placed over the major muscle groups, including the quadriceps femoris (midpoint between the anterior superior iliac spine and patella), hamstrings (proximal posterior thigh), gluteus maximus (upper outer quadrant of the buttock), erector spinae (lumbar region, lateral to the spine), abdominals (around the umbilical region), pectoralis major (centered on the midclavicular line), latissimus dorsi (mid-posterior axillary line), deltoideus (mid-deltoid belly), biceps brachii (mid-belly of the anterior arm), and triceps brachii (posterior upper arm). Electrodes were aligned parallel to the direction of muscle fibers to maximize stimulation efficiency.

Table 1.

Overview of the 20-week electromyostimulation training program across four phases.

Phase	Weeks	Warm-up	Main EMS	Focus
Phase 1	1–5	3 min – dynamic stretch +30 % MTI	50–60 % MTI, 4s on/6s off	Familiarization, neural activation
Phase 2	6–10	3 min – dynamic stretch +35 % MTI	60–65 % MTI, 5s on/5s off	Initial strength development
Phase 3	11–15	3 min – lunges +40 % MTI	65–75 % MTI, 6s on/4s off	Hypertrophy and power
Phase 4	16–20	3 min – high-intensity stretch +45 % MTI	70–80 % MTI, 7s on/3s off	Max strength and composition gains

Abbreviations: EMS = Electrical Muscle Stimulation; MTI = Maximal Tolerated Intensity; s = seconds; min = minutes.

EMS sessions were performed in a standing upright position with slight knee flexion (∼10–20°) to ensure a stable and natural posture, minimize joint stress, and optimize muscle engagement. The stimulation phase itself was conducted statically, with participants maintaining a steady posture without dynamic movements during active stimulation. A dynamic warm-up involving low-intensity EMS and mobility exercises preceded the main training phase but was completed without simultaneous high-intensity stimulation.

2.3.2. Session structure and parameters

Each EMS session followed a structured format consisting of a 3-min warm-up, a 20-min main training phase, and a 2-min cool-down. To support progressive neuromuscular and morphological adaptations over time, the stimulation parameters were systematically adjusted across the four 5-week training phases.

The stimulation frequency was maintained between 80 and 85 Hz throughout the intervention, a range optimized for activating high-threshold motor units and promoting strength development. Pulse width was set between 350 and 400 μs to ensure sufficient muscle fiber recruitment while maintaining participant comfort.

Training intensity was gradually increased over the course of the program. In Phase 1, the intensity began at approximately 50–60 % of the participant's maximal tolerated intensity (MTI), and it progressively rose to 70–80 % MTI by Phase 4. This progression was individualized based on perceived exertion, as monitored using the Borg CR10 scale, with a target exertion level between 5 (moderate) and 8 (very hard).

Duty cycles were also adjusted across phases to balance stimulation and recovery. Specifically, the stimulation/rest intervals were set at 4 s on and 6 s off during Phase 1, then progressed to 5s/5s in Phase 2, 6s/4s in Phase 3, and finally 7s/3s in Phase 4. Additionally, a ramp-up time of 0.3–0.5 s was used in all sessions to allow for a gradual onset of stimulation, reducing the risk of discomfort or muscle spasms.

2.3.3. Phased training protocol (20 Weeks)

The intervention was divided into four progressive 5-week phases, each designed to maximize neuromuscular adaptation and prevent training plateaus.

2.3.3.1. Phase 1 (Weeks 1–5): initial adaptation

The warm-up in this phase consisted of low-intensity EMS stimulation (40–50 Hz, 200 μs, 30 % MTI) combined with dynamic stretching exercises such as leg swings and bodyweight squats. The main 20-min training block employed EMS at 80–85 Hz and 350–400 μs pulse width, with an intensity set at 50–60 % of the participant's maximal tolerated intensity (MTI). Muscle activation followed a structured sequence, beginning with quadriceps and hamstrings stimulation from minutes 3 to 7, gluteus maximus and erector spinae from minutes 7 to 11, latissimus dorsi, pectoralis major, and deltoids from minutes 11 to 15, followed by triceps, biceps, and abdominals from minutes 15 to 19. The final minutes (19–23) repeated stimulation of the quadriceps and hamstrings. The session concluded with a 2-min cool-down using low-intensity EMS (40–50 Hz, 200 μs, 30 % MTI) paired with static stretching. This phase primarily aimed to familiarize participants with EMS application, enhance neural activation, and ensure comfort during stimulation.

2.3.3.2. Phase 2 (Weeks 6–10): strength development

The warm-up protocol remained similar to Phase 1 but with a slightly elevated stimulation intensity of 35 % MTI. The main training session again lasted 20 min and used EMS at 80–85 Hz and 350–400 μs, with intensity increased to 60–65 % MTI. A duty cycle of 5 s on and 5 s off was applied. The muscle activation sequence was identical to Phase 1; however, each contraction bout featured a higher intensity and slightly longer duration to promote increased neuromuscular demand. The cool-down mirrored the previous phase, consisting of low-intensity EMS and static stretching. The focus during this phase was to build foundational strength and improve muscular endurance.

2.3.3.3. Phase 3 (Weeks 11–15): hypertrophy and power

In this phase, the warm-up incorporated lunges and additional mobility exercises, accompanied by EMS set at 40 % MTI. The main EMS training block maintained the same frequency (80–85 Hz) and pulse width (350–400 μs), but intensity was further increased to 65–75 % MTI, with a duty cycle of 6 s on and 4 s off. Compared to earlier phases, greater emphasis was placed on quadriceps and abdominal muscle groups, each receiving four stimulation cycles. The cool-down included EMS at 35 % MTI and extended static stretching to aid in recovery. The primary objective of this phase was to promote muscular hypertrophy and improve power output.

2.3.3.4. Phase 4 (Weeks 16–20): peak performance

The final phase began with a warm-up comprising high-intensity dynamic stretching and EMS at 45 % MTI. The 20-min main training continued with EMS at 80–85 Hz and 350–400 μs, with stimulation intensity elevated to 70–80 % MTI and a duty cycle of 7 s on and 3 s off. Maximum tolerable intensity was applied uniformly to all major muscle groups, with each receiving four activation cycles. The session concluded with a recovery-focused 2-min cool-down, using EMS at 40 % MTI combined with static stretching. This phase aimed to optimize strength, muscle endurance, and body composition adaptations in preparation for final assessments.

2.3.4. Progression and safety measures

To prevent neuromuscular fatigue and training plateaus, intensity and duty cycles were progressively increased across phases based on adaptations observed in previous EMS studies.^11,15,21 During EMS sessions, if participants reported a perceived exertion lower than 5/10 on the Borg CR10 scale, the stimulation intensity was increased by approximately 5–10 % of the maximal tolerated intensity (MTI) at the next stimulation cycle. If perceived exertion reached 8/10 or higher, the stimulation was immediately terminated to ensure participant safety and minimize risk of excessive fatigue. Training compliance was high, with participants completing at least 90 % of the scheduled sessions. Safety monitoring protocols were strictly enforced throughout the intervention. Sessions were immediately halted if the Borg CR10 scale exceeded a value of 8, or if participants reported discomfort, cramping, or unintended muscle spasms. Additionally, any signs of excessive fatigue or potential injury risk prompted immediate cessation of the session. Although no biochemical safety markers (e.g., creatine kinase) were measured, training was conducted under strict supervision using progressive loading protocols, with real-time monitoring and immediate cessation criteria to ensure participant safety. No adverse events were reported throughout the intervention.

2.4. Traditional resistance training (TradRT) protocol

TradRT protocol was implemented twice weekly over a 20-week period, designed to enhance muscle strength and body composition through a progressive full-body program (Table 2). The protocol was informed by established resistance training principles^3,22,23 and supervised by certified strength and conditioning specialists to ensure safety and efficacy. Training sessions were conducted using standard gym equipment, with weights adjusted based on individual 1-repetition maximum (1RM) assessments performed biweekly.

Table 2.

Overview of the 20-week traditional resistance training program across four phases.

Phase	Weeks	Warm-up	Main EMS	Focus
Phase 1	1–5	3 sets × 15–20 reps	50–60 % 1RM	Muscular endurance, adaptation
Phase 2	6–10	3 sets × 12–15 reps	60–70 % 1RM	Hypertrophy initiation
Phase 3	11–15	4 sets × 10–12 reps	70–80 % 1RM	Strength-hypertrophy balance
Phase 4	16–20	4 sets × 8–10 reps	80–90 % 1RM	Maximal strength development

Abbreviations: 1RM = One Repetition Maximum.

2.4.1. Session structure and parameters

Each 90-min resistance training session consisted of three segments: a 10- to 15-min warm-up, a 60-min main training phase, and a 10-min cool-down. Throughout the 20-week period, training parameters were progressively modified. Training intensity increased from 60 to 70 % of 1RM in Phase 1 to 75–85 % 1RM in Phase 4, based on regular 1RM testing. Participants performed 3 sets per exercise, with repetition ranges adjusted across phases—starting at 12–15 repetitions in Phase 1 and transitioning to 10–12 repetitions in later phases. The tempo for each movement was standardized, consisting of a 1–2 s concentric phase followed by a 2–3 s eccentric phase. Rest intervals ranged from 90 to 120 s between sets and were extended to 120 s for compound exercises such as the leg press.

2.4.1.1. Phase 1 (Weeks 1–5): anatomical adaptation

This phase began with a warm-up that included 5–10 min of light aerobic exercise (e.g., treadmill or stationary bike), followed by dynamic stretching exercises such as leg swings, arm circles, and bodyweight squats. The main training phase included eight resistance exercises: Smith machine bench press, machine shoulder press, machine lat pulldown, machine leg press, leg curl, machine biceps curl, triceps pushdown, and abdominal machine work. Each exercise was performed for three sets of 15–20 repetitions at 60–70 % 1RM, except for the abdominal machine, which was adjusted for muscular endurance and performed for three sets of 25–30 repetitions at 50–60 % 1RM. The session concluded with a cool-down involving 5 min of light cardio and 5 min of static stretching, primarily targeting the hamstrings and quadriceps. The main objective of this phase was to enhance joint stability, neuromuscular coordination, and prepare participants for higher training loads in subsequent phases.

2.4.1.2. Phase 2 (Weeks 6–10): hypertrophy foundation

The warm-up and cool-down protocols remained identical to those used in Phase 1. The main training component included nine exercises performed in three sets: leg press, incline chest press, seated row, shoulder press, leg curl, biceps curl, triceps pushdown, seated abdominal crunch, and deadlift (which was newly introduced in this phase). Resistance ranged from 65 to 75 % 1RM, with repetition targets adjusted per exercise type. While most movements were performed for 12–15 repetitions, biceps curls and triceps pushdowns were executed for slightly higher repetitions (15–20), and abdominal exercises were carried out for 20–25 repetitions at slightly lower intensity (55–65 % 1RM). This phase aimed to establish a hypertrophy base and improve muscular endurance.

2.4.1.3. Phase 3 (Weeks 11–15): strength development

This phase retained the same warm-up and cool-down structure as the earlier phases. The primary training component involved nine exercises: leg press, bench press, lat pulldown, shoulder press, hamstring curl, biceps curl, triceps pushdown, cable abdominal twists, and squat (added in this phase). Exercises were performed for three sets of 10–12 repetitions at 70–80 % 1RM, except for biceps curls and triceps pushdowns, which were performed for 12–15 repetitions, and cable abdominal twists, which targeted 20–25 repetitions at 60–70 % 1RM. This phase focused on developing maximal strength while maintaining muscular balance across major movement patterns.

2.4.1.4. Phase 4 (Weeks 16–20): peak performance

The warm-up and cool-down routines remained consistent with previous phases. The main training session comprised nine resistance exercises: leg press, incline bench press, seated row, lateral raise, hamstring curl, biceps curl, triceps pushdown, cable abdominal twist, and deadlift. Each exercise was performed for three sets, with repetition ranges adjusted to 8–10 for most compound lifts and 12–15 for smaller muscle group exercises such as lateral raise, biceps curl, and triceps pushdown. Abdominal work targeted 20–25 repetitions at 65–75 % 1RM. Training intensity during this final phase was increased to 75–85 % 1RM, aiming to optimize strength, power output, and readiness for post-intervention assessments.

2.4.2. Progression and safety

Throughout the 20-week training program, progression was systematically managed by reassessing participants’ 1RM values every two weeks. If participants were able to complete all prescribed repetitions with proper form, the training load was increased by approximately 5–10 % to ensure continued overload. In line with standard periodization principles, the repetition ranges were gradually reduced from 15 to 20 repetitions in the early phases to 8–10 repetitions in later phases, reflecting a shift in emphasis from muscular hypertrophy to maximal strength development.

All training sessions were closely supervised to monitor for signs of overtraining or compromised technique. When deviations in form or symptoms of fatigue were observed, loads were adjusted accordingly to ensure participant safety and maintain training quality. No adverse events were reported during the intervention. Although emergency medical support was available on-site as a precautionary measure, no incidents requiring medical intervention occurred throughout the study period.

2.5. Outcome measures

The effects of EMS and TradRT on body composition and strength performance were assessed over a 20-week period by trained research personnel blinded to group allocation, with measurements taken at baseline (pre-intervention), 10 weeks (midpoint), and 20 weeks (post-intervention).

2.5.1. Body composition assessment

Body composition variables, including body weight (kg), BMI (kg/m²), and body fat percentage (%), were measured using a multi-frequency bioelectrical impedance analysis (BIA) device (TANITA MC-780MA, Tokyo, Japan). This device has been validated as a reliable and valid tool for assessing body composition in sports and clinical research settings.^24,25 Measurements were conducted in a climate-controlled environment (20–22 °C, 40–60 % humidity) between 8:00–10:00 a.m. to minimize diurnal variation. Prior to each measurement, participants were instructed to avoid eating, drinking, strenuous exercise, alcohol, and caffeine for at least 24 h and to empty their bladder before the assessment. All BIA measurements were conducted in a standing position with bare feet, wearing standardized lightweight clothing (e.g., shorts and a T-shirt). The same clothing type was worn across all measurement sessions to ensure consistency.

2.5.2. Strength performance assessment

Muscular strength was evaluated using estimated 1RM values for bench press, leg press, shoulder press, biceps curl, triceps pushdown, and abdominal strength (cable crunch). Since direct 1RM testing may pose an injury risk for untrained individuals, submaximal strength testing was performed using the Brzycki equation²⁶:

$$1RM=\frac{WeightLifted\times 36}{37-Repetitions}$$

Each participant performed 5–8 repetitions at a challenging submaximal weight, and their 1RM was estimated using this formula. To ensure reliability, participants were given three attempts with 2-min rest intervals between trials, and the highest calculated 1RM value was recorded.

All assessments followed standardized protocols recommended by the American College of Sports Medicine²⁷ for body composition and strength testing. Participants received standardized instructions and demonstrations before each test to ensure consistency in execution. A 5-min warm-up, consisting of light aerobic exercise (e.g., treadmill walking at 50–60 % maximal heart rate) and dynamic stretching (e.g., leg swings, arm circles, bodyweight squats), was performed before strength testing to reduce injury risk and enhance measurement consistency.

2.6. Statistical analysis

All statistical analyses were performed using SPSS version 27.0 (IBM Corp., Armonk, NY, USA), with a significance level set at α = 0.05. Data were tested for normality using the Shapiro-Wilk test, and appropriate parametric methods were applied. Descriptive statistics, including means and standard deviations, were calculated for all outcome measures at baseline, 10 weeks, and 20 weeks. To evaluate the effects of EMS and TradRT on body composition and strength performance over time, a two-way mixed-model analysis of variance (ANOVA) with repeated measures was conducted. The between-subjects factor was the training group (EMS vs. TradRT), and the within-subjects factor was time (baseline, 10 weeks, 20 weeks). In this context, the time effect reflects overall changes across all participants over the three time points, independent of group assignment. The group effect assesses whether there are consistent differences between EMS and TradRT groups, regardless of the measurement time point. The time × group interaction effect, on the other hand, evaluates whether the pattern of change over time differs between groups, which allows the identification of distinct adaptation trajectories specific to each training modality. Where significant main effects or interactions were detected (p < 0.05), Bonferroni-corrected post-hoc pairwise comparisons were conducted to determine specific time-based changes within each group and between-group differences at individual time points. The effect size was estimated using partial eta-squared (ηp²), with values of 0.01, 0.06, and 0.14 interpreted as small, medium, and large effects, respectively. The Bonferroni correction was applied to maintain the family-wise error rate at α = 0.05 across multiple comparisons. Additionally, Hedges' g effect sizes were calculated to quantify the magnitude of pre-post changes within each group, interpreted using the Hopkins classification: trivial (<0.2), small (0.2–0.6), moderate (0.6–1.2), large (1.2–2.0), very large (2.0–4.0), and extremely large (>4.0).

3. Results

The effects of EMS and TradRT on anthropometric and body composition measures were evaluated over a 20-week period. Table 3 presents the mean ± standard deviation values for weight, BMI, and fat percentage at baseline, 10 weeks, and 20 weeks for both groups.

Table 3.

Changes in weight, BMI, and fat percentage over 20 Weeks in EMS and traditional resistance training groups.

	Group	Baseline	At 10 Weeks	At 20 Weeks	Statistical Analysis (F-values, P-values, ${\mathit{\eta }}_{\mathit{p}}^{\mathbf{2}}$)
Weight (kg)	EMS (n = 24)	85.4 ± 19.9	84.2 ± 19.6	82.8 ± 19.5	Time effect: F = 379.529; p = 0.000; ${\eta }_p^2$ = 0.896 Group effect: F = 0.300; p = 0.587; ${\eta }_p^2$ = 0.007 Group∗Time Interaction: F = 28.799; p = 0.000; ${\eta }_p^2$ = 0.396
	TradRT (n = 22)	84.3 ± 15.2	83.3 ± 15.5	84.6 ± 15.7
BMI	EMS (n = 24)	29.0 ± 5.8	28.6 ± 5.7	28.1 ± 5.7	Time effect: F = 73.414; p = 0.000; ${\eta }_p^2$ = 0.625 Group effect: F = 0.000; p = 0.999; ${\eta }_p^2$ = 0.000 Group∗Time Interaction: F = 111.966; p = 0.000; ${\eta }_p^2$ = 0.718
	TradRT (n = 22)	28.20 ± 5.0	27.8 ± 4.9	28.1 ± 4.7
Fat (%)	EMS (n = 24)	25.9 ± 10.0	23.08 ± 9.4	20.5 ± 8.9	Time effect: F = 22.458; p = 0.000; ${\eta }_p^2$ = 0.338 Group effect: F = 0.128; p = 0.722; ${\eta }_p^2$ = 0.003 Group∗Time Interaction: F = 14.325; p = 0.000; ${\eta }_p^2$ = 0.246
	TradRT (n = 22)	26.6 ± 9.4	21.7 ± 7.8	17.0 ± 6.2

Data are presented as mean ± standard deviation. p < 0.05 is considered statistically significant. ${\eta }_p^2$: 0.01 indicates a small effect, 0.06 a medium effect, and 0.14 a large effect. EMS = Electrical Muscle Stimulation; TradRT = Traditional Resistance Training.

Weight showed a significant time effect (F = 379.529, p < 0.001, ηp² = 0.896), indicating a large effect of the intervention period across both groups. However, no significant group effect was observed (F = 0.300, p = 0.587, ηp² = 0.007), suggesting similar weight changes between EMS and TradRT groups. A significant time × group interaction was found (F = 28.799, p < 0.001, ηp² = 0.396), indicating that the pattern of weight change differed between the groups over time. Specifically, the EMS group exhibited a decrease in weight from 85.4 ± 19.9 kg at baseline to 82.8 ± 19.5 kg at 20 weeks, while the TradRT group showed a slight increase from 84.3 ± 15.2 kg to 84.6 ± 15.7 kg.

BMI also demonstrated a significant time effect (F = 73.414, p < 0.001, ηp² = 0.625), reflecting a large effect of the intervention duration. There was no significant group effect (F = 0.000, p = 0.999, ηp² = 0.000), but a highly significant time × group interaction was observed (F = 111.966, p < 0.001, ηp² = 0.718), indicating distinct BMI trajectories between groups. The EMS group's BMI decreased from 29.0 ± 5.8 kg/m² at baseline to 28.1 ± 5.7 kg/m² at 20 weeks, whereas the TradRT group's BMI remained relatively stable, changing from 28.20 ± 5.0 kg/m² to 28.1 ± 4.7 kg/m².

Fat percentage exhibited a significant time effect (F = 22.458, p < 0.001, ηp² = 0.338), with a medium effect size, suggesting a notable reduction over the 20-week period. No significant group effect was found (F = 0.128, p = 0.722, ηp² = 0.003), but a significant time × group interaction was detected (F = 14.325, p < 0.001, ηp² = 0.246), indicating different fat percentage changes between groups. The EMS group showed a decrease from 25.9 ± 10.0 % at baseline to 20.5 ± 8.9 % at 20 weeks, while the TradRT group experienced a more pronounced reduction from 26.6 ± 9.4 % to 17.0 ± 6.2 %.

The impact of EMS and TradRT on strength performance was assessed over a 20-week period. Fig. 1 displays the changes in strength measures—including bench press, leg press, shoulder press, biceps curl, triceps pushdown, and abdominal exercises—at baseline, 10 weeks, and 20 weeks in both groups.

Fig. 1.

Changes in strength performance over 20 Weeks in EMS and traditional resistance training groups.

Bench press strength showed a significant time effect (F = 310.815, p < 0.001, ηp² = 0.876), indicating a large effect of the intervention period across both groups. No significant group effect was found (F = 1.098, p = 0.301, ηp² = 0.024), while a significant time × group interaction was detected (F = 11.400, p < 0.001, ηp² = 0.206). The EMS group demonstrated an increase from 44.8 ± 12.1 kg at baseline to 57.7 ± 11.4 kg at 20 weeks, while the TradRT group improved from 45.2 ± 12.4 kg to 63.4 ± 14.0 kg.

Leg press strength exhibited a significant time effect (F = 75.864, p < 0.001, ηp² = 0.633), reflecting a large effect over the intervention period. No significant group effect was found (F = 1.018, p = 0.319, ηp² = 0.023), but a significant time × group interaction was present (F = 5.783, p = 0.004, ηp² = 0.116), indicating different progression rates. The EMS group's leg press strength rose from 120.8 ± 35.6 kg to 147.5 ± 53.2 kg, whereas the TradRT group increased from 123.0 ± 31.8 kg to 169.8 ± 48.5 kg.

Shoulder press strength demonstrated a significant time effect (F = 52.866, p < 0.001, ηp² = 0.546), with a large effect size. No significant group effect was found (F = 0.902, p = 0.347, ηp² = 0.020), but a significant time × group interaction emerged (F = 8.198, p < 0.001, ηp² = 0.157), indicating divergent trends. The EMS group improved from 39.0 ± 13.7 kg to 45.4 ± 19.0 kg, while the TradRT group increased from 39.8 ± 11.6 kg to 54.1 ± 17.9 kg.

Biceps curl strength showed a significant time effect (F = 94.869, p < 0.001, ηp² = 0.683), indicating a large effect. No significant group effect was found (F = 0.409, p = 0.526, ηp² = 0.009), while the time × group interaction was not significant (F = 2.211, p = 0.116, ηp² = 0.048). The EMS group's strength increased from 23.8 ± 7.7 kg to 30.9 ± 11.4 kg, while the TradRT group rose from 23.9 ± 6.8 kg to 33.6 ± 10.2 kg.

Triceps pushdown strength exhibited a significant time effect (F = 64.352, p < 0.001, ηp² = 0.594), with a large effect size. No significant group effect was found (F = 1.311, p = 0.258, ηp² = 0.029), but a significant time × group interaction was detected (F = 8.706, p < 0.001, ηp² = 0.165), indicating different strength gains. The EMS group showed an increase from 33.6 ± 9.9 kg to 39.7 ± 14.6 kg, while the TradRT group improved from 34.1 ± 8.8 kg to 47.1 ± 13.6 kg.

Abdominal strength demonstrated a significant time effect (F = 51.879, p < 0.001, ηp² = 0.541), indicating a large effect size. No significant group effect was found (F = 1.027, p = 0.317, ηp² = 0.023), but a significant time × group interaction was present (F = 7.505, p < 0.001, ηp² = 0.146), suggesting varying improvement patterns. The EMS group increased from 29.0 ± 9.7 kg to 33.9 ± 13.9 kg, while the TradRT group rose from 29.6 ± 8.4 kg to 40.3 ± 12.7 kg.

To quantify the magnitude of within-group changes, Hedges' g effect sizes were calculated and interpreted using Hopkins’ classification: trivial (<0.2), small (0.2–0.6), moderate (0.6–1.2), large (1.2–2.0), very large (2.0–4.0), and extremely large (>4.0). In the EMS group, body weight (g = −2.60) and BMI (g = −2.59) showed very large reductions, while fat percentage decreased with an extremely large effect (g = −3.80), reflecting substantial improvements in body composition. In contrast, the TradRT group exhibited a small increase in body weight (g = 0.35), a trivial decrease in BMI (g = −0.12), and a very large reduction in fat percentage (g = −2.75).

Strength gains were observed in both groups across all tested exercises. In the EMS group, bench press strength improved with a very large effect (g = 2.46), while biceps curl (g = 1.28) and leg press (g = 0.97) showed large and moderate effects, respectively. Shoulder press (g = 0.74), triceps pushdown (g = 0.80), and abdominal strength (g = 0.74) also demonstrated moderate effects, highlighting notable upper-body strength improvements. The TradRT group demonstrated greater strength increases overall, with very large effect sizes for bench press (g = 3.63), biceps curl (g = 1.81), triceps pushdown (g = 1.78), leg press (g = 1.76), shoulder press (g = 1.65), and abdominal strength (g = 1.60).

4. Discussion

EMS and TradRT are two distinct training modalities that have gained increasing attention in sports science due to their potential effects on muscle strength and body composition. Traditional resistance training has long been regarded as the gold standard for improving muscular strength, hypertrophy, and body composition, while EMS presents a time-efficient alternative that induces muscle contractions via electrical impulses, allowing for simultaneous activation of multiple muscle groups.^11,17,19,28 This characteristic makes EMS particularly attractive for individuals with limited time availability, those recovering from injuries, or those seeking to supplement their regular training regimens.^11,29 However, there is limited research directly comparing the adaptation patterns and effectiveness of EMS versus traditional resistance training, particularly within multi-week longitudinal interventions. The present study aimed to compare the effects of 20 weeks of EMS and TradRT on body composition and strength performance to determine the relative efficacy of each method. By evaluating changes in weight, BMI, fat percentage, and muscular strength across multiple time points, this study provides critical insights into the effectiveness and implementation potential of EMS during a structured, multi-week training program. Given the growing interest in alternative training methods that optimize neuromuscular adaptations with minimal mechanical stress, this study contributes valuable data to the ongoing debate regarding the role of EMS as a viable training modality in both recreational and athletic populations.^11,18,28 Previous studies have shown that EMS may enhance muscular strength and alter body composition, but the magnitude of these effects varies depending on individual factors, training duration, and stimulation parameters.²⁹ By directly comparing EMS and TradRT under standardized conditions, our findings offer a deeper understanding of their respective advantages and limitations. This study not only provides evidence for the efficacy of EMS in improving body composition and muscle strength but also offers practical implications for training program design in sports performance, rehabilitation, and general fitness. The insights gained from this research may help athletes, coaches, and exercise professionals optimize training protocols for different populations and objectives.

The present study demonstrated significant changes in body weight and BMI over the 20-week intervention period, with distinct patterns of adaptation between the EMS and TradRT groups. Both groups exhibited a significant time effect, indicating that body weight and BMI improved consistently across all participants over time, regardless of group assignment, which suggests that prolonged training induced meaningful anthropometric adaptations. These findings are in line with previous research demonstrating the efficacy of EMS and TradRT in reducing body fat and improving body composition, particularly in untrained populations.^11,30 Whole-body EMS has been reported to increase metabolic rate and energy expenditure by stimulating a larger muscle mass simultaneously, which may contribute to reductions in fat mass and overall body weight²⁹ In contrast, resistance training is often associated with lean mass accretion, which may offset reductions in total body weight despite reductions in fat percentage.^10,22,31 The significant time × group interaction for weight suggests that the trajectory of weight change differed between EMS and TradRT, with EMS being more effective for weight loss, while TradRT supports body recomposition. Although dietary intake was not strictly controlled, participants’ 3-day food diaries indicated general stability in caloric intake and macronutrient distribution, with three participants excluded for repeated deviations (>20 % change from baseline). This approach minimized dietary confounding while preserving real-world relevance. Remaining variations in diet were minor and unlikely to fully account for the observed outcomes, reinforcing the role of training modalities. Future studies with detailed nutritional tracking could further elucidate diet-training interactions.

The findings of this study revealed a significant reduction in fat percentage over the 20-week intervention period in both EMS and TradRT groups, with a significant time effect, indicating that fat percentage decreased over time across all participants, regardless of training modality. However, the reduction in body fat was more pronounced in the TradRT group compared to the EMS group, as indicated by a significant time × group interaction, suggesting that the magnitude and pattern of fat loss varied between the two groups, with TradRT producing a more substantial decline. The EMS group exhibited a fat percentage decrease from 25.9 ± 10.0 % at baseline to 20.5 ± 8.9 % at 20 weeks, whereas the TradRT group demonstrated a greater reduction from 26.6 ± 9.4 % to 17.0 ± 6.2 % (Hedges' g = −3.80 and −2.75, respectively; both classified as ‘very large’ effects). These findings are consistent with previous research suggesting that resistance training plays a pivotal role in fat mass reduction by increasing muscle mass and resting metabolic rate, leading to greater overall energy expenditure.^11,32 The relatively smaller reduction in fat percentage observed in the EMS group may be attributed to differences in energy expenditure mechanisms between the two modalities. While EMS has been shown to enhance muscle activation and induce metabolic demand during and after exercise,^29,33,34 it may not elicit the same degree of sustained post-exercise oxygen consumption (EPOC) as high-intensity resistance training. Whole-body EMS has been reported to acutely elevate metabolic rate and fat oxidation, though evidence regarding its fat loss effects beyond short-term interventions remains inconclusive.^35,36 A recent meta-analysis on EMS training confirmed moderate fat reduction effects, particularly in sedentary and overweight individuals, yet emphasized the need for combined interventions that include resistance training for maximal benefits.³⁰ Moreover, the observed differences in fat percentage reduction could also be related to neuromuscular recruitment patterns. EMS preferentially stimulates type II muscle fibers, which are metabolically more active and have a higher capacity for glucose uptake and glycogen depletion.^34,35,37 However, it is important to note that these mechanistic interpretations are based on prior literature and were not directly assessed in the present study. Future research incorporating physiological measures such as EMG, oxygen kinetics, or muscle biopsy would be required to confirm these pathways.^28,29,38 Consequently, while EMS appears to be an effective tool for reducing fat percentage, its impact may be further optimized when integrated with traditional resistance training, particularly in contexts where mechanical loading is feasible and desirable.

The results of this study revealed significant improvements in strength performance across all measured exercises (bench press, leg press, shoulder press, biceps curl, triceps pushdown, and abdominal strength) over the 20-week intervention period. A significant time effect was observed in all strength parameters, indicating that both EMS and TradRT induced meaningful strength adaptations (Hedges’ g values ranged from 0.74 to 2.46 in the EMS group and from 1.60 to 3.63 in the TradRT group; classified as moderate to very large effects, suggesting practically relevant improvements across all strength measures). Additionally, the group × time interaction was significant for all strength measures except biceps curl, with TradRT leading to greater strength gains compared to EMS. These findings align with previous research indicating that while EMS is effective for enhancing muscle activation and strength, traditional resistance training remains superior for maximal strength development due to progressive overload and mechanical stress.^11,18 The greater strength improvements in the TradRT group may be explained by well-established principles of mechanical loading and neuromuscular adaptation. Resistance training involves external loads requiring active force generation, eccentric-concentric contractions, and progressive increases in resistance. According to previous literature, this loading pattern has been shown to stimulate muscle hypertrophy, tendon adaptation, and neuromuscular efficiency, which are proposed as key contributors to strength development.^4,32 In contrast, EMS primarily induces isometric contractions by electrically stimulating motor neurons. Although this method is effective for muscle activation, it may not elicit the same mechanical and metabolic stimuli associated with dynamic, high-resistance training.^13,33

However, despite the lower absolute strength gains observed in the EMS group, the improvements were still statistically and practically significant, supporting EMS as a viable training modality for strength enhancement, particularly in populations with limited access to conventional resistance training. Previous studies have demonstrated that EMS-induced strength gains are more pronounced in untrained individuals or sedentary populations, whereas trained individuals may require higher EMS intensities or combined approaches to maximize adaptations.^16,39 Additionally, it has been suggested that EMS preferentially activates Type II muscle fibers, which are crucial for explosive force production but may require additional mechanical loading for optimal hypertrophy.²⁰ However, this mechanistic explanation is based on prior research and was not directly examined in the present study. Further investigation using neuromuscular assessments would be necessary to confirm such fiber-specific activation patterns. Although EMS may offer benefits in situations where conventional resistance training is not feasible—such as among individuals with orthopedic limitations, chronic pain, or restricted mobility—these specific scenarios were not directly addressed in this study. Furthermore, EMS is not universally accessible; it often requires specialized equipment, trained personnel, and may be cost-prohibitive in many contexts. These factors may limit its practical application as a widespread alternative to resistance training. Future studies should evaluate the feasibility, cost-effectiveness, and user acceptability of EMS in diverse populations to determine in which settings it may serve as a viable adjunct or alternative to traditional training methods. Given these findings, EMS can be considered an effective adjunct to resistance training rather than a standalone replacement. Although hybrid training models—combining EMS and resistance training—have shown promising results in previous studies, such approaches were not evaluated in this study. Future research should explore the potential of combined interventions to enhance strength gains across different populations.^11,18 Additionally, recent studies have explored the benefits of combining EMS with voluntary dynamic exercises, known as whole-body EMS with movement integration.^11,40,41 This approach may enhance functional neuromuscular adaptations and improve the transferability of strength gains to dynamic performance. Future studies comparing static versus dynamic EMS applications could provide valuable insights for optimizing training protocols.

The distinct adaptation patterns observed between the EMS and TradRT groups can be attributed to fundamental physiological differences in how each training modality stimulates muscle activation and neuromuscular adaptation.^4,28 While both methods elicited significant improvements in strength and body composition over the 20-week period, the underlying mechanisms driving these adaptations have been suggested to differ in prior research. Traditional resistance training relies on progressive overload, wherein external resistance provides mechanical stress that stimulates hypertrophy through muscle fiber recruitment, mechanical tension, and metabolic stress. This process promotes both structural (myofibrillar hypertrophy) and neuromuscular adaptations, leading to enhanced motor unit synchronization, firing rates, and intermuscular coordination.^42,43 As a result, resistance training elicits robust progressive strength development, particularly in multi-joint compound exercises such as the bench press and leg press, where higher levels of external loading can be progressively applied. Conversely, EMS stimulates muscle contractions via electrical impulses, bypassing voluntary neuromuscular activation and directly depolarizing motor neurons.^30,34 This method preferentially activates Type II muscle fibers, which are highly responsive to high-intensity contractions but also more susceptible to fatigue.^44,45 EMS training has been shown to enhance motor unit recruitment efficiency, particularly in individuals with lower baseline strength levels, by reducing the activation threshold for high-threshold motor units.^13,44 However, since EMS-induced contractions are predominantly isometric and externally driven, they lack the eccentric muscle actions critical for hypertrophy and progressive strength adaptation. Additionally, the absence of progressive mechanical overload may limit muscle architectural changes, such as increases in pennation angle and fascicle length, which are essential for long-term strength gains.^37,46 Importantly, it should be noted that these mechanistic explanations are derived from previous studies and were not directly assessed in the present investigation. Future research incorporating physiological and morphological assessments (e.g., EMG, muscle architecture, or biochemical markers) is needed to confirm these proposed mechanisms.

Another key difference between the two modalities lies in metabolic and hormonal responses. Traditional resistance training is associated with higher EPOC and hormonal changes, including increases in growth hormone, testosterone, and IGF-1, which play a crucial role in muscle hypertrophy and recovery.^17,32 EMS, despite inducing high muscle activation levels, does not generate the same systemic metabolic demand as resistance training, which may explain why fat loss was more pronounced in the TradRT group. Additionally, neural adaptations appear to differ between the two methods. While resistance training enhances rate coding, intermuscular coordination, and central nervous system drive, EMS-induced strength gains are largely attributed to enhanced muscle fiber recruitment and intramuscular coordination rather than improvements in voluntary neural activation.^16,28,47 The observed differences in adaptation patterns suggest that combining EMS with traditional resistance training may provide complementary neuromuscular stimuli. While previous studies have reported that hybrid training models^29,48—where EMS is integrated into conventional strength training—can lead to enhanced strength and muscle mass gains compared to EMS or resistance training alone, this hypothesis was not tested in our study. Future research is warranted to evaluate the efficacy and feasibility of such combined approaches across different populations.

4.1. Strengths and limitations

This study has several strengths, including its intervention duration (20 weeks), which allowed for meaningful physiological adaptations, and its high adherence rate, ensuring the reliability of the findings. The use of standardized assessment protocols for strength and body composition, along with the inclusion of multiple time points (baseline, 10 weeks, and 20 weeks), provided a comprehensive analysis of the effects of EMS and TradRT over time. Additionally, the randomized group allocation based on body fat percentage minimized potential baseline differences, enhancing the study's internal validity. However, certain limitations should be acknowledged. The absence of a non-exercising control group prevents conclusions about the independent effects of time or lifestyle factors. Although dietary intake was monitored through simplified 3-day food diaries and participants with repeated significant deviations (>20 % change from baseline) were excluded, precise control over caloric intake and macronutrient composition was not enforced. This may have introduced minor variability in body composition outcomes, though the general stability of reported diets suggests a limited confounding effect. Additionally, overall physical activity levels outside the intervention were not tracked, which could have influenced results. Finally, while the study focused on strength and body composition, it did not assess neuromuscular adaptations, muscle architecture, or metabolic responses, which could provide deeper insights into the underlying mechanisms of EMS and TradRT adaptations. Moreover, no biochemical safety markers such as creatine kinase were measured to monitor potential muscular stress, particularly in the EMS group. Although no adverse events were reported and strict supervision protocols were followed, future studies should incorporate objective biomarkers to more comprehensively assess the physiological safety of EMS interventions. Additionally, it is important to acknowledge that comparing the progression of training intensity between EMS and traditional resistance training presents inherent limitations. Since muscular adaptations are influenced by multiple physiological stimuli beyond just external load or stimulation parameters, the intensity responses observed under each training modality may not be directly comparable. Therefore, while both interventions led to positive outcomes, the distinct nature of their stimuli complicates intensity-based comparisons and interpretation of dose–response relationships. Future research should also include hormonal, neuromuscular, and long-term retention measures, along with more detailed nutritional tracking, to further explore the differential effects and safety profiles of these training modalities.

5. Conclusion

The findings of this study provide practical implications for individuals, coaches, and healthcare professionals seeking effective training methods for strength development and body composition improvements. EMS training was shown to be a viable alternative for individuals who may struggle with conventional resistance training due to time constraints, injuries, or physical limitations. However, for individuals prioritizing maximal strength and fat loss, traditional resistance training remains the more effective approach, likely due to its progressive overload and greater metabolic impact. While hybrid training models combining EMS and traditional resistance methods have been suggested in the literature as potentially beneficial, this approach was not evaluated in the current study and thus remains speculative. Future research is warranted to investigate whether such combinations could enhance training efficiency or outcomes in various populations. Future research should also explore the optimal periodization of EMS, its effects on neuromuscular and metabolic markers, and long-term retention of strength adaptations. Moreover, investigating the impact of different EMS intensities, frequencies, and contraction modalities could further refine training protocols and maximize its effectiveness across various populations.

Ethics approval and consent to participate

The authors would like to express their gratitude to all participants who took part in this study and demonstrated commitment throughout the 20-week training period. Special thanks to the Erzurum Technical University Scientific Research and Publication Ethics Committee for reviewing and approving this study (Meeting No: 08, Decision No: 3, Date: 04.07.2024).

Consent for publication

This manuscript does not contain any individual person's identifiable data or images. Therefore, no specific consent for publication was required.

Availability of data and material

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Funding

None.

Declarations of competing interest

None.