LACTATE KINETICS DURING PASSIVE AND PARTIALLY ACTIVE RECOVERY IN ENDURANCE AND SPRINT ATHLETES

We investigated the effects of passive and partially active recovery o n lactate removal after exhausting cycle ergometer exercise in enduran ce and sprint athletes. A group of 14 men, 7 endurance-trained (ET) an d 7 sprint-trained (ST), performed two maximal incremental exercise te sts followed by either passive recovery (20 min seated on cycle ergome ter followed by 40 min more of seated rest) or partially active recove ry [20 min of pedalling at 40% maximal oxygen uptake (VO2max) followed by 40 min of seated rest]. Venous blood samples were drawn at 5 min a nd 1 min prior to exercise, at the end of exercise, and during recover y at 1, 2, 3, 4, 5, 6, 8, 10, 15, 20, 30, 40, 50, 60 min post-exercise . The time course of changes in lactate concentration during the recov ery phases were fitted by a bi-exponential time function to assess the velocity constant of the slowly decreasing component (tau(2)) express ing the rate of blood lactate removal. The results showed that at the end of maximal exercise and during the Ist min of recovery, ET showed higher blood lactate concentrations than ST. Furthermore, ET reached s ignificantly higher maximal exercise intensities [5.1 (SEM 0.5) W . kg (-1) vs 4.0 (SEM 0.3) W . kg(-1), P< 0.05] and VO2max [68.4 (SEM 1.1) ml . kg(-1). min(-1) vs 55.5 (SEM 5.1) ml . kg(-1). min(-)1, P < 0.01] . There was no significant difference between the two groups during pa ssive recovery for tau(2). During partially active recovery, tau(2) wa s higher than during passive recovery for both groups (P < 0.001), but ET recovered faster and sooner than ST (P < 0.05). Compared to passiv e recovery, the tau(2) measured during partially active recovery was i ncreased threefold in ET and only 1.5-fold in ST. We concluded that pa rtially active recovery potentiates the enhanced ability to remove blo od lactate induced by endurance training.