Short and Long-Term Interval Effects of High-Intensity Interval Training on Pathways Related to Telomere Homeostasis in Rat Skeletal Muscle

Abstract

Background: Exercise training through various mechanisms leads to correct telomere homeostasis. The potential role of high-intensity interval training (HIIT) to keep up the telomere length has not been recognized in skeletal muscle. Objectives: This study investigated the influence of eight weeks of HIIT with short-term interval (HIITSh) and long-term interval (HIITL), and four weeks of detraining on the regulation of some pathways maintaining telomere length in skeletal muscle. Methods: Fifty-four male Wistar rats were randomly assigned into HIITSh, HIITL, and control groups. Rats were sacrificed after the end of the intervention (eight weeks of training and four weeks of detraining). Gastrocnemius muscle was collected, and telomerase activity, p53 protein, total oxidative status (TOS), and total antioxidant capacity (TAC) levels were measured. Results: We found no change in telomerase activity, p53, TOS, and TAC levels in both HIIT groups compared to the control group (P > 0.05). In addition, the p53 level was higher in the detrained HIITSh group than the control group (P = 0.004), and the TOS level was higher in the detrained HIITSh group than both HIIT groups. Conclusions: Short-term HIIT does not improve telomere length and some pathways contributing to maintaining telomere length in skeletal muscle. The training protocol’s duration is an essential factor in activating telomerase as a mechanism to keep up telomere length in skeletal muscle.