Abstract
An increase in endogenous androgen production has been observed following long-term
physical training and the beneficial effects of training have been attributed in part
to this phenomenon. Other investigators, however, found, in contrast lower testosterone
levels in trained compared with untrained subjects. The purpose of the present study
was to follow the long-term changes in total testosterone (T) and Cortisol (C) levels
in intensely training individuals. The changes in the body's anabolic state, induced
by intense long-term physical training, were determined using the plasma resting T/C
ratio. T and C levels of 35 young untrained subjects were measured at 6 week intervals
during 18 weeks of strenuous physical training. All samples were drawn within one
half hour of awaking (05.30-06.00). Mean serum T levels increased significantly at
6 weeks (28.7%, p < 0.02) and decreased significantly at 12 weeks (20.6%, p < 0.02),
but did not differ at 18 weeks compared with levels before training was commenced
(mean±SE, 16.9±0.2, 21.8±0.3, 12.8+0.2 and 17.3±0.2 nmol/l at 0, 6, 12, and 18 weeks,
respectively). Mean serum C was increased significantly (21.3%, p < 0.005) at 18 weeks
(463.5±19.3, 507.7±22.1, 480.1±19.3, and 565.6±22.1 nmol/l). T/C ratio decreased significantly
after 12 and 18 weeks of training. Our results do not support an association between
reduced total testosterone levels and prolonged training. However, hypercorticolism
with a relative catabolic state may occur.
Key words
Testosterone - cortisol - anabolic androgens - long-term training
