Abstract
To provide information on the duration of the regeneration phase after several hours
of physical strain, venous blood samples of eight participants in a 1/4 triathlon
competition were taken each day at the same time (arrival) for determinations of testosterone
(T), SHBG, and cortisol (C). In addition, urea, creatinine, creatinine kinase, and
the changes in plasma volume were determined. Directly after arrival, T had not changed
substantially, but decreased nonsignificantly on each of the following days and obtained
the lowest concentration on the 2nd day after the triathlon. T/SHBG as an expression
of free testosterone was significantly reduced on the 2nd, 3rd, and 4th days after
the competition. C increased up until the end of the competition by 4.5 times the
original value, and during the subsequent days it decreased again to the normal range.
Until the end of the observation period on the 4th day after the competition, urea
was still significantly elevated. The data suggest an anabolic deficit lasting for
several days as a result of prolonged physical strain.
Key words
testosterone - cortisol - triathlon - anabolic-catabolic relationship - regeneration
phase
