Differences in lactate exchange and removal abilities in athletes specialised in different track running events (100 to 1500 m).

The purpose of this study was to investigate whether track running specialisation could be associated with differences in the ability to exchange and remove lactate. Thirty-four male high-level runners were divided into two groups according to their specialty (100 - 400 m/800 - 1500 m). All performed a 1-min 25.2 km x h -1 event, followed by a 90-min passive recovery to obtain individual blood lactate recovery curves which were fitted to a bi-exponential time function: La = La + A 1 (1-e -gamma1t) + A 2 (1-e -gamma2t). The velocity constant gamma 1 which denotes the ability to exchange lactate between the previously worked muscles and blood was higher (p < 0.001) in middle-distance runners than in sprint runners. The velocity constant gamma 2 which reflects the overall ability to remove lactate did not differ significantly between the two groups. gamma 1 was positively correlated with the best performance over 800 m achieved by 16 athletes during the outdoor track season following the protocol (r = 0.55, p < 0.05). In conclusion, the lactate exchange ability seems to play a role on the athlete's capacity to sustain exercise close to 2-min-duration and specifically to run 800 m.