Hormonal responses of combining endurance-resistance exercise in healthy young men.

This study investigated the influence of resistance (R) following endurance (E) exercise or ER on acute hormonal responses, such as growth hormone (GH), total testosterone (TT), free testosterone (FT), IGF-1, and cortisol. Ten healthy young men with an average age of 23.9 years (±0.7 y), a height of 175 cm (±3.3 cm), a weight of 74.4 kg (±4.3 kg), and a body mass index of 25.5 kg/m2 (±0.65 kg/m2) participated in this study. All of the participants took part in four protocols (R, E, ER, and control) in separate sessions with at least 1-week intervals. Blood samples were collected before, immediately after exercise, and 15 minutes after exercise in the R, E, ER, and control group protocols. GH, lactate, TT, and FT increased in the R protocol, and GH, lactate, FT, and IGF-1 increased significantly in the E and ER protocols (P<0.05). FFA increased only after the E protocol (P<0.05). Cortisol significantly decreased in the ER, E, and control group protocols (P<0.05). In conclusion GH, TT and cortisol responses to R following E exercise were reduced. This effect might be due to increase in FFA. However It seems that IGF-1 has not inhibited by FFA.