King Grub
2014-02-19, 08:31
The aim of this study was to investigate the effects of a resistance training program with excessive training load and insufficient recovery time between bouts on muscle hypertrophy- and atrophy-related protein expression. Male Wistar rats were randomly assigned to either a trained (TR, N = 9) or a sedentary (SE, N = 9) group. The TR group was subjected to a 12-week resistance training program with excessive training load and insufficient recovery between bouts that was designed to induce plantaris muscle atrophy. After the 12-week experiment, the plantaris muscle was collected to analyze the cross-sectional area (CSA) of the muscle fibers, and MAFbx, MyoD, myogenin and IGF-I protein expression (Western blot). The CSA was reduced significantly (-17%, P < 0.05) in the TR group compared to the SE group. Reciprocally, there was a significant (P < 0.05) 20% increase in MAFbx protein expression, while the MyoD (-27%), myogenin (-29%) and IGF-I (-43%) protein levels decreased significantly (P < 0.05) in the TR group compared to the SE group. In conclusion, our data indicated that muscle atrophy induced by resistance training with excessive training load and insufficient recovery was associated with upregulation of the MAFbx catabolic protein and downregulation of the MyoD, myogenin and IGF-I anabolic proteins. These findings suggest that quantitative analysis of these proteins can be important and complementary with other biochemical markers to confirm a possible overtraining diagnosis.
J Strength Cond Res. 2014 Feb 12. RESISTANCE TRAINING WITH EXCESSIVE TRAINING LOAD AND INSUFFICIENT RECOVERY ALTERS SKELETAL MUSCLE MASS-RELATED PROTEIN EXPRESSION.
J Strength Cond Res. 2014 Feb 12. RESISTANCE TRAINING WITH EXCESSIVE TRAINING LOAD AND INSUFFICIENT RECOVERY ALTERS SKELETAL MUSCLE MASS-RELATED PROTEIN EXPRESSION.