EXERCISE AND GONADAL-FUNCTION

Exercise is associated with release of a number of pituitary and hypot halamic hormones and a decline in the concentration of luteinizing hor mone (LH). Follicle stimulating hormone (FSH) is generally not influen ced by exercise. Serum inhibin concentrations, which are reciprocally influenced by serum FSH concentrations, are increased in some animals but are unchanged after acute exercise in human males. Teleologically, the decline in gonadotrophic hormone (LH) secretion after exercise ma y be geared to enhance individual survival over species propagation in times of stress, analogous to the postulated 'fight or flight' reacti on. The decrease in gonadotrophic hormone (LH) secretion is believed t o be due to changes in gonadotrophin releasing hormone (GnRH) pulse fr equency and amplitude, particularly in women, who often develop amenor rhoea. Males have less dramatic changes in their hypothalamic-pituitar y-gonadal axis, although a significant decrease in serum testosterone in physically conditioned males can usually be demonstrated. In this u pdate possible mechanisms for the decline in gonadotrophin secretion w ith exercise are briefly discussed.