Endocrine response to intense interval exercise

This investigation provides an insight into the physiological changes produced, and processes operating, during and after a typical interval exercise training regime. The role of interval exercise in the modulation of the plasma concentration of sex hormone binding globulin (SHBG) and the hormones β-oestradiol, testosterone, prolactin and growth hormone was assessed. Eight trained male athletes [mean maximal oxygen uptake ( {Mathematical expression}O_2max 64.3 (SD 3.8) ml·kg^-1·min^-1, mean age 31.5 (SD 4.5) years] undertook an intense interval exercise (treadmill running) protocol to exhaustion. Subjects completed an average of 15.6×1-min runs. This interval protocol produced significant increase in the plasma concentration of SHBG and all four hormones (all P<0.01) in the immediate post-test period. The plasma concentration of the hormones increased as indicated: β-oestradiol (45%), testosterone (38%), prolactin (230%), growth hormone (2000%). These hormones have an established capacity to interact with components of many physiological systems and, as such, may provide a mechanism for the changes induced by intense exercise in many of these systems.