The effect of 8 weeks of resistance training on muscle function and some proteins related to sarcopenia in soleus muscle of obese aged male rats

  Resistance training is one of the most effective methods to reduce fat tissue and   prevention of reducing muscle mass and strength loss (sarcopenia). The aim of this study was to investigate the effect of 8 weeks of resistance training on protein amounts of FOXO3, Murf1 and Atrogin-1 and also muscle strength of obese aged male rats.

Out of 30 Wistar male rats (age: 15 months and weight: 320 to 350 grams), 10 were separated as control group and the rest became obese under a high-fat diet for 12 weeks.  Then the obese rats (with Lee index higher than 310) were divided into two groups: obese control and resistance training. The resistance training group performed training program (ladder-climbing) for 8 weeks, 3 sessions per week (3 sets of 8 reps with %25, %50, %75 and %100 of body weight). The amounts of FOXO3, Murf1 and Arogin-1 proteins were measured by ELISA method in soleus muscle. muscle strength was also measured by forelimb grip strength test. The levels of protein were analyzed using ANOVA and Tukey and muscle strength were analyzed with ANCOVA and Bonferroni post hoc test.

Compared to the control group, obesity increased FOXO3, Murf1 and Arogin-1 proteins (p=0.000) and decreased muscle strength (p=0.000) in the obese control group. on the other hand, resistance training decreased the values of FOXO3 (p=0.003), Murf1 (p=0.005) and Arogin-1 (p=0.012) and increased forelimb grip strength (p=0.000) in the training group compared to the obese control group.

Although obesity increased muscle atrophy markers, the results of this research showed that resistance training plays an important role in maintaining muscle mass and increasing muscle strength in obese aged rats by reducing muscle atrophy markers.