1 Universidad de São Paulo, Brasil.
Background: Resistance exercise promotes health benefits for general population. However, heavy resistance training can induce severe damage, including cellular death. This scenario may be reverted by improvement of the cytoprotective 70 kDa heat shock protein (HSP70) expression that regulates protein homeostasis. Supplementation with L-glutamine and L-alanine, both in their free form or as a dipeptide can increase the HSP70 expression in heavy aerobic training. Conversely, less is known about these effects in resistance training. Purpose: Determine the effects of oral chronic supplementation with L-glutamine and L-alanine, both in their free form or as dipeptide on HSP70 expression in tibialis of rats submitted to heavy resistance training. Methods: Adult male Wistar rats were subjected to heavy resistance training for 6 weeks and supplemented with L-glutamine and L-alanine as a dipeptide or in their free form (DIP, GLN+ALA and ALA groups, respectively), or water (CTRL, group). Resistance training consisted to climb a ladder from 3 to 6 sets with progressive loads (25% to 100% of body weight). In the last 21 days of training supplements were given in a 4% solution dissolved in drinking water. HSP70 expression was determined in tibialis muscle. Results: Heavy resistance training induced HSP70 response compared to sedentary animals (p<0.05). On the other hand, supplementations enhanced that response, increasing HSP70 expression in GLN+ALA (24.8%) and DIP (30.3%) groups compared to CTRL group (p<0.05). Conclusión: Chronic oral supplementation with L-glutamine and L-alanine, both in their free form or as a dipeptide, improves HSP70 muscle expression in rats submitted to heavy resistance training.