Blood lactate and heat stress during training in rowers.

The purpose of the present study was to test the hypothesis that large increases in blood lactate concentration ([La] (b)) and/or body temperature may occur during an endurance training on a rowing ergometer and disrupt training. The influence of an increase in air convection on the capacity to perform a prolonged exercise was also explored. Ten trained oarsmen were asked to undergo twice, in control (C) and increased air ventilation (AV) conditions, two 30-min trainings on a rowing ergometer at a work rate corresponding to 2.5 mmol . L (-1) of [La] (b) determined during a previous incremental exercise (P (2.5)). Four subjects did not complete the training session in C despite a steady state in [La] (b) in two of them. In these four subjects, the end of the exercise was associated with the highest measured rectal temperatures (T (re), 39.4 +/- 0.1 degrees C) and rate of perceived exertion (RPE, 17.8 +/- 0.3). Regarding the six other subjects, their heart rate, oxygen uptake, RPE, T (re) and water loss values were lower (p < 0.05) in AV than in C. [La] (b) displayed the same profile in C and AV. This study suggests that i) high body temperature may constitute a significant factor of perceived exertion and disrupt indoor training session, and ii) capacity to perform an endurance training on a rowing ergometer was improved by increasing air convection.