Abstract: The effect of physical exercise on male reproduction is usually dual. Rational exercise is beneficial to reproductive endocrinology, whilst overload exercise usually damages male fertility. Physical exercise at a reasonable amount remarkably increases the levels of FSH, LH and T, improves the microenvironment of the testis, and alters the epigenetic modifications of sperm cells for the benefit of offspring. However, excessive exercise elevates the temperature of the testicular microenvironment, and the induced heat stress can impair the sperm structure and function that eventually lead to male infertility. Furthermore, excessive exercise can also inhibit the functions of GnRH neurons and pituitary and interfere in the secretion of reproductive hormones. Besides, physical exercise causes significant demethylation of genes related to sperm DNA CpG island, which affect the expressions of microRNAs and epigentics. The research progress of the effects of exercise on male reproduction and the underlying mechanisms were discussed in this review.

Key words: Male, Spermatogenesis, Reproduction, Exercise, Obesity