Research in Sport Medicine and Technology

---

Muscle atrophy is one of the consequences of aging and sports activities may prevent it. The aim of this study was to evaluate the effect of high intensity interval training on gene expression of Tweak and Fn14 in EDL muscle of aged C57bl/6 mice. For this purpose, 28 male C57bl/6 mice aged (n=14) and adult (n=14) were assigned in two groups of training (n=7) and control (n=7). After one-week familiarization, training groups participate in 4 weeks high intensity training program on treadmill, with an intensity of 85% of the maximum speed in the first week up to 95% of the maximum speed in the last week, in 2-minute intervals (6 in the first week to 10 in the last week) with 1 minute rest between intervals. 48 hours after the last training session, the mice were sacrificed. Then gene expressions of Tweak and Fn14 in EDL muscle were measured. The findings show that aging has significant effect on EDL muscle weight (P=0.032).  Also the results showed that with increasing age Tweak and Fn14 mRNA expression increased in the EDL muscle (P=0.001 and P=0.002 respectivly). On the other hand, training can reduce Tweak and Fn14 gene expression in both old and adult groups (P=0.001). On the other hand, although training slightly increased EDL muscle weight in both adult (P=0.117) and old (P=0.321) groups, this value statistically was not significant. Thus, aging is associated with an increase in Tweak and Fn14 mRNA expression, which could possibly be involved in muscle weight changes associated with aging. Since that high intensity interval training decrease these mRNA expression, can might be utilized HIIT for maintenance aging and adult of muscle mass.