نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Extended Abstract
Background and Aim: Overweight is a growing global problem, especially in developing countries. The World Health Organization (WHO) considers obesity one of the top ten risk factors for life-threatening diseases. Research has shown that being overweight is closely linked to conditions such as menopause. In this regard, Lambrinoudaki et al. (2018) noted that menopause and aging independently contribute to weight gain, which serves as a foundation for many diseases. Given the hormonal changes during menopause, limited research has explored the effects of exercise interventions in postmenopausal individuals. Thus, focusing on exercise training to improve biochemical, physiological, and psychological indicators in overweight and obese postmenopausal women is particularly important. Due to the existing research gaps, the researchers conducted this study to examine the effects of resistance training on plasma CRP levels, body composition indices, and self-efficacy in overweight and obese postmenopausal women.
Materials and Methods: This is an applied, quasi-experimental study with a pre-test-post-test design involving 56 overweight and obese postmenopausal women (aged 45–65 years, BMI≥25). Participants were randomly divided into two groups: a home-based resistance training group (n=28) and a control group (n=28). After attending an informational session, the subjects in the training group began resistance exercises at home.
The training group performed home-based resistance training for four weeks (28 sessions of 90 minutes each at moderate intensity), which included the following exercises: squats, lunges, standing leg raises, biceps curls, back curls, swimming motions, side and back muscle rotations, and deadlifts. Each movement was performed with a two-second eccentric (lengthening) phase, a two-second pause at the midpoint, and a two-second concentric (shortening) phase. The exercises were conducted in three sets of 12 repetitions, with 1–1.5 minutes of rest between sets. Each exercise station lasted approximately 10 minutes.
Before and after the intervention, CRP plasma levels were measured via blood sampling after 12–14 hours of fasting at two time points: before the training program began and after four weeks of training in both the control and training groups. In the initial phase, participants were instructed to avoid strenuous physical activity for 48 hours prior to testing. In the second phase, following the training period and with a 24-hour interval after the last session, blood sampling was repeated under identical conditions to the first phase.
Body composition indices—including weight, body mass index (BMI), waist-to-hip ratio (WHR), and circumferences of the waist, hip, abdomen, upper arm, chest, and thigh—were measured. Self-efficacy was assessed using the standardized Scherer et al. (1982) questionnaire. Data were analyzed using ANCOVA and dependent t-tests at a significance level of p<0.05.
Findings: The results of the Shapiro-Wilk test, used to assess the normality of the data distribution for CRP variable scores in the study, showed that the null hypothesis of a normal distribution was retained (p=0.57), indicating that the data followed a normal distribution. In contrast, the Levene’s test results for body composition indices indicated a violation of the homogeneity of variances assumption. Accordingly, a dependent t-test was used to analyze the effect of four weeks of training on body composition indices (p≥0.05).
The self-efficacy test results showed that the null hypothesis of a normal distribution was retained for both groups. The findings revealed that after four weeks of home-based resistance training, no significant change was observed in CRP levels. Additionally, there was no significant difference in the mean CRP inflammatory index scores between the training group (post-test: 3.84; pre-test: 3.98) and the control group.
The analysis of covariance results indicated that after four weeks of training, there was no significant difference in CRP inflammatory index levels between the groups. However, a significant decrease was observed in WHR, as well as in chest, hip, arm, thigh, and waist circumferences. In contrast, changes in weight, BMI, and abdominal circumference were not significant. No significant differences were observed in any of the measured variables in the control group.
The results demonstrated that resistance training significantly increased self-efficacy and its components. Furthermore, after controlling for pre-test scores, the difference in mean self-efficacy scores between the training and control groups was significant (p≥0.05), with a group effect of 19%, indicating the influence of the independent variable (training) on the dependent variable (self-efficacy).
Conclusion: According to the results, it seems that moderate-intensity resistance training, even in short-term periods, can simultaneously affect the physiological (body composition regulation) and psychological (self-efficacy enhancement) dimensions of menopausal women as a non-pharmacological and low-cost strategy. This approach, especially in populations at risk of metabolic and psychological complications of menopause, can be a bridge between exercise interventions and comprehensive health promotion. In other words, resistance training at home can improve the physical and mental health of menopausal women and is recommended as an effective strategy in managing menopausal complications and overweight.
Ethical Considerations: This article is the result of a research project entitled “the effect of four weeks of home resistance training on health-promoting lifestyle, self-efficacy, and corona anxiety, and some inflammatory indicators in overweight and obese postmenopausal women,” which was implemented with the support of the University of Birjand. It is worth noting that all ethical principles have been considered in this article, and the participants were informed about the purpose of the research and its implementation stages.
Compliance with ethical guideline: In this study, all experiments were conducted in accordance with the regulations of the Research Ethics Committee of Birjand University.
Funding: This study was conducted with financial support from the University of Birjand.
Conflicts of interest: The authors declare that there is no conflict of interest in this research.
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