Comparison of effect of modified German volume, high-intensity, and non-linear resistance training on some biochemical, anthropometric, and functional indices related to muscle strength in male athletes

Resistance training (RT) plays a major role in developing muscle mass and strength. This study aimed to compare the effect of eight weeks of modified German volume resistance training (MGVRT), high-intensity resistance training (HIRT), and non-linear resistance training (NLRT) on the serum levels of myostatin (Mstn), follistatin (FLS), nuclear factor kappa B (N F-κB), and muscle mass and strength in male athletes.

Forty young men bodybuilders were randomly assigned into equal groups, including MGVRT, HIRT, NLRT, and control. Training protocols were performed for eight weeks (three times a week). Selected biochemical variables, muscle mass, and strength were measured before and 48 hours after the last training session. For statistical analyses the analysis of covariance, repeated-measures analysis of variance, Kruskal-Wallis, and Mann-Whitney U test‏s were and significance level was set as p≤0.05.

The Mstn and FLS protein levels significantly decreased and increased, respectively in all three experimental groups compared with the control group. Moreover, the NF-κB level was significantly lower in the MGVRT and HIRT groups than NLRT and control groups. Furthermore, the arm and thigh circumference and muscular strength in the chest press and squat movements significantly increased in all three experimental groups as compared with the control group where the increase in arm circumference in the MGVRT group was significantly higher than in the HIRT and NLRT groups and as the same the muscular strength in the HIRT group was significantly higher than in the MGVRT and NLRT groups.

All three RT protocols lead to improve biochemical, anthropometric, and functional indices in male athletes, but the MGVRT and HIRT protocols led to more increase in muscular hypertrophy and maximum strength, respectively. However, further studies are needed on the relationship between RT protocols with muscle mass and strength, and the biochemical parameters associated with them.