During nine months of training preceding the 1988 Olympic Games, six elite male rowers were regularly subjected to an investigation to changes in the rest values of the free testosterone/cortisol ratio (FTCR). In addition, the rowers were subjected to an exercise test on rowing ergometer. When comparing the FTCR levels through the season with the initial level, the results show that during periods of heavy training (training camp) the rest levels of the FTCR decrease (range 5-50%) in most of the rowers. During periods of less intensive training, the opposite is the case for the behaviour of the FTCR. The FTCR value never dropped below 0.35*10(-3), a value which is considered to be the threshold of overstrain. Moreover, decreases in the FTCR of more than 30% relative to preceding values were often found. These decreases are not indicative for overstrain but should be related to temporary incomplete recovery from intensive training. However, it remains to be demonstrated that periods of prolonged decreases (several months) in the level of the FTCR may finally lead to a situation of overstrain or overtraining in an athlete. Power at 4.0 mmol lactate (P4.0) and maximal power (PM) did not show a relation with the hormonal parameters.