Testosterone is a steroid hormone that is secreted in men from the testes in a circadian fashion. Secretion of testosterone from the testes is indirectly controlled by the hypothalamus. In order for secretion to occur from the testes, the hypothalamus must first secrete leutinizing hormone-releasing hormone. Previous research has consistently shown increases in serum testosterone concentration following acute resistance exercise. Testosterone is affected by a combination of factors including the amount of muscle tissue mass stimulated, volume of exercise performed, and intensity of exercise. Testosterone plays important regulatory roles in muscle protein metabolism and influences neuromuscular trainability. There is a circadian rhythm of testosterone, but to date no data exist as to the effects of resistance exercise on the diurnal cycle of testosterone. This area of study should be investigated further in order to gain greater understanding of how resistance exercise affects testosterone responses over the course of a entire day.
(C) 1998 National Strength and Conditioning Association