Effects of work/rest interval manipulation of high-intensity interval training and detraining on telomerase activity and p53 levels in cardiac muscle

Objectives. - Exercise training is a well-known method for the prevention and delay of many age-related diseases such as cardiovascular diseases. High-intensity interval training (HIIT) has attracted much attention due to its numerous benefits. Manipulating of work/rest interval duration for understanding of the best biochemical responses on cellular anti-senescent pathways in rat heart muscle is important. Equipment and methods. - Fifty-four male Wistar rats (12 weeks) were assigned to three groups: HIIT with short-term interval (HIITS: sixteen 1-min work at 80-90% VO2max separated by 1-min rest at 50-60% VO2max), HIIT with long-term interval (HIITL: four 4-min work at 80-90% VO2max separated by 4-min rest at 50-60% VO2max) and control. Rats were sacrificed after training protocol (eight weeks) and at the end of the four weeks detraining, then the heart tissue was isolated to measure the telomerase enzyme activity and p53 protein level. Results. -The telomerase activity after HIITS and HIITL, and following four weeks detraining did not change significantly. The level of p53 protein in the HIITL group was significantly higher than that of the two other groups. After the detraining period, the observed increase in the HIITL group tended to decrease. Conclusion. - It seems that HIIT with short- and long-term intervals in short training periods does not change the telomerase enzyme activity in the heart muscle; so, increasing p53 protein following long-term HIIT does not result in telomere shortening. (C) 2019 Elsevier Masson SAS. All rights reserved.