Journal of Exercise & Organ Cross Talk

Abstract This study examined the acute hormonal and myokine responses to traditional and circuit resistance training in young males with distinct BMI-based groups. Twenty sedentary men aged 20–30 years were classified as high-BMI (BMI >29.9) or low-BMI (BMI <18.5). Each participant completed both traditional resistance training (TRT) and circuit resistance training (CRT) protocols in a crossover design, with a one-week washout period. Sessions included multi-joint upper and lower body exercises at comparable intensities. Blood samples were taken immediately before and after each session. Serum levels of testosterone, cortisol, myostatin, and follistatin were assessed using ELISA kits. A repeated-measures ANOVA was used to compare within- and between-group changes across time and training modality. Baseline cortisol levels were significantly higher in low-BMI individuals (P=0.037), while testosterone levels showed no initial difference between groups (P>0.05). Post-TRT, testosterone levels increased significantly in high-BMI individuals compared to low-BMI individuals (P=0.017), with both training types elevating testosterone and cortisol across all participants (P<0.05). CRT led to a significant reduction in myostatin and increase in follistatin in high-BMI individuals (P<0.05), while only follistatin increased significantly in low-BMI individuals after TRT (P<0.05). These results suggest that CRT promotes superior anabolic signaling in high-BMI individuals, while TRT is more effective at enhancing testosterone response. Myokine and hormonal responses appear to be body-type-dependent and training-modality-specific. Practitioners designing hypertrophy-focused programs should tailor training protocols to the athlete’s BMI-based group to optimize muscle adaptation and endocrine outcomes. And also, trainers should individualize hypertrophy programs based on body composition to optimize both hormonal responses and muscle adaptation.

Abstract The study aimed to compare the acute effects of low resistance exercises with partial and complete blood flow restriction (BFR) and heavy resistance exercise on growth hormone (GH), myostatin, testosterone, and cortisol in competitive wrestlers. Forty elite wrestlers were randomly divided into four groups (n=10); low resistance training with complete BFR (LRT+CBFR), low resistance training with partial BFR (LRT+PBFR), low resistance training (LRT), and heavy resistance training (HRT). Blood samples were collected before and after the intervention, and a specific ELISA kit measured variables. Analysis of covariance and paired t-test was performed to analyze the data. There were no significant differences in the variables between the four interventions. Intra-group results showed a significant decrease in myostatin levels in the HRT group (p=0.02), and a significant increase in GH in the LRT+CBFR (p=0.02) and LRT+PBFR (p=0.03), testosterone in the HRT group (p=0.04) and cortisol in the three groups LRT+CBFR (p=0.02), LRT+PBFR (p=0.01) and HRT (p=0.04). Despite the similarity of the changes in the four interventions, due to the percentage of changes, it seems that low resistance training with BFR could produce similar anabolic effects to high-intensity resistance training.

Abstract The main purpose of this study was to investigate the effect of primary swimming on the hormonal anabolic-catabolic balance and serum leptin in obese children and adolescents. Sixty obese subjects (children and adolescents) were randomly assigned to one of four groups: 1) Primary swimming training (children); 2) control (children); 3) Primary swimming training (adolescents); and 4) control (adolescents) groups. Our experimental subjects performed a primary swimming training for 8 weeks, 3 sessions per week and 60 minutes per session. Before and after training period, blood samples, anthropometric and body composition measurements were taken in fasting state from all subjects. The findings showed that the primary swimming training prevents significant increase of serum leptin and insulin hormone in adolescents. Furthermore, primary swimming training caused a significant decrease in body fat percent, body fat mass and body mass index, a significant increase of VO_2max in children and adolescents, a significant decrease in cortisol hormone as well as a significant increase in fat free mass in adolescents (p<0.05). There was a positive and significant correlation between levels of leptin changes and body fat percent and fat mass after primary swimming training (p<0.05). In addition, there was a negative and significant correlation between levels of leptin hormone changes and fat free mass after primary swimming training (p<0.05). Therefore, it can be concluded that eight weeks of primary swimming training improves serum leptin and some of the anthropometric, hormonal and metabolic parameters.

Abstract The current study aimed to compare the effect of hypertrophy-, strength-, and power-type resistance exercise in resistance-trained women with considering cortisol and androgen cross talk. After one-repetition maximum (1-RM) estimation, ten resistance-trained women (age: 26.30 ± 4.95 years; body mass index: 22.07 ± 2.02 kg/m2; body fat: 24.64 ± 4.98%) conducted hypertrophy- (70% of 1-RM), strength- (90% of 1-RM), and power-type (45% of 1-RM) resistance exercise for three consecutive weeks. The movements included lever leg extension, reverse-grip lat pull-down, horizontal leg press, standing biceps cable curl, lying leg curl, machines bench press, standing cable triceps extension, and seated calf raises. Fasting blood was taken before and immediately after each trial. Statistical analyses were performed at a significance level of P