Effect of eight weeks of resistance training on the expression of klotho protein and insulin-like growth factor 1 genes in slow twitch and fast twitch skeletal muscles of aged Wistar rats

Background and Aims: Klotho protein is a substance effective in increasing life expectancy. Moreover, it prevents muscle atrophy, osteoporosis, and cardiovascular disease. Therefore, the present aimed to assess changes in the expression of klotho protein and insulin-like growth factor 1 (IGF-1) genes in the muscles of aged Wistar rats after eight weeks of resistance training. Materials and Methods: The present experimental study was connected on 16 Wistar male rats, aged 20 months, which were assigned to two groups of resistance training group and control. Resistance training was performed three sessions a week over eight weeks. After dissecting the rats, the soleus and flexor hallucis longus muscles of the rats were extracted to measure the expression of klotho protein and (IGF-1) genes using the real-time polymerase chain reaction technique. Results: After the resistance training program, Klotho protein in the fast-twitch muscle tissue of the trained rats did not show a significant difference, compared to that in the control group. Furthermore, IGF-1 in the fast-twitch and slow-twitch muscles of the training group did not display a marked difference, compared to that in the control group. Conclusion: As evidenced by the obtained results, the values of klotho protein and IGF-1 did not improve after a period of resistance training. It can be argued that resistance training should be conducted in longer periods and with different intensities, which should be scrutinized in future research.