چكيده لاتين
Abstract
The aim of the present study was to investigate the effects of a three-month whole-body electromyostimulation (WB-EMS) training program on body composition and gene expression levels of appetite-related hormones in overweight men. This semi-experimental study employed a pre-test–post-test design with a control group. The statistical population consisted of men aged 30 to 50 years, residing in Isfahan, with a body mass index (BMI) of approximately 29.35. A total of 28 participants were randomly assigned to an experimental group (n = 15) and a control group (n = 13). The experimental group performed WB-EMS training three times per week for three months (each session lasting 45 minutes), including warm-up, resistance exercises, and cool-down phases. The intensity of electrical stimulation was adjusted according to each individualʹs tolerance using an X-Body device. The control group did not receive any intervention during this period.
Body composition indices including weight, BMI, skeletal muscle mass (SMM), lean body mass (LBM), total body water (TBW), and body fat mass (MBF) were assessed using a body composition analyzer at the beginning and end of the intervention. Additionally, to evaluate the gene expression levels of appetite-related hormones (leptin, ghrelin, and orexin), blood samples were collected and analyzed using Real-Time PCR.
The results showed that WB-EMS training led to a significant reduction in weight (p = 0.014) and a significant increase in SMM (p = 0.003), with a highly significant time × group interaction (p < 0.001) in both variables. LBM also increased significantly (p = 0.021), while TBW did not show a statistically significant change (p = 0.055). Although changes in BMI over time were not statistically significant, the time × group interaction was significant (p = 0.003). Regarding MBF, a significant effect of time was observed for its reduction (Sig = 0.001, F = 7.758, η² = 0.303), but the interaction between time and group was not significant (Sig = 0.080, F = 3.075, η² = 0.131). This suggests that although body fat decreased over the course of the study, the difference between the experimental and control groups was not statistically significant.
At the molecular level, leptin gene expression significantly decreased (t = -2.142, p = 0.043, d = -0.878), likely reflecting a reduction in body fat. In contrast, ghrelin gene expression showed a significant increase (t = 2.450, p = 0.023, d = 1.004), which may indicate activation of the bodyʹs regulatory energy responses under negative energy balance conditions. Furthermore, a significant increase in orexin gene expression (t = 2.933, p < 0.001, d = 1.202) suggests enhanced alertness, increased motor motivation, and higher energy expenditure as a result of EMS training.
Overall, the findings of this study indicate that WB-EMS training over a three-month period, even without high levels of active participation, can improve body composition and influence gene expression pathways involved in appetite regulation and energy balance. Therefore, it can be considered a non-pharmacological and effective intervention in managing overweight in men.
Keywords: Whole-body electromyostimulation (WB-EMS), Body composition, Appetite hormones, Leptin, ghrelin, Orexin, Body fat mass (MBF), Overweight men
