Introduction: The aim of this study was to evaluate the effect of high intensity interval training on gene expression of Sema3A in EDL muscles of aged C57bl/6 mice.

Materials & methods: For this purpose, twenty male C57bl/6 mice aged (n=10) and adult (n=10) were assigned in two groups of training and control. After one-week familiarization, training groups participate in four weeks high intensity training program and forty-eight hours. After the last training session, the mice were sacrificed. Then Gene expressions of Sema3A in EDL muscles were measured with Real time PCR technique.

Findings: The results showed that with increasing age Sema3A mRNA expression increased in the EDL muscle (P=0.001). But training can reduce its expression in both adult (P=0.105) and old (P=0.025) groups. Although, in adult mice was not statistically significant. In addition, the findings show that aging has significant effect on EDL muscle weight, and significant difference between adult and old control groups was observed (P=0.032). On the other hand, although training slightly increased EDL muscles weight in both adult (P=0.117) and old (P=0.321) groups, this value statistically was not significant.

Discussion & conclusions: Aging is associated with an increase in expression of Sema3A, which could possibly be involved in neuromuscular changes in aging. Moreover, high intensity interval training by recruited fast fiber muscle types can modify Sema3A mRNA expression and probably reduce denervation and muscle atrophy in aging process.