Lactate kinetics after short strenuous exercise in man.

Arterial blood lactate was measured at 10 s time intervals after a 3 min strenuous exercise for six athletes pedaling a bicycle ergometer in the sitting position. Recovery curves were fitted to the equation: Y(t) = A1(1-e-gamma1t)+A2(1-e-gamma2t)(0). The evolution of arterial lactate concentrations during recovery can accurately be represented by this equation. The values of the coefficients A and gamma found were used for a numerical application to an open two-compartment model: the "working muscle space" (1) and the "lactate space" (2). Intramuscular concentrations, the transfer coefficients from compartment 1 to compartment 2 and from compartment 2 to compartment 1 and the fractional turnover and basal turnover rate were calculated. Computed intramuscular lactate concentrations at the end of exercise compare favorably with those found earlier by muscular biopsic samplings. The turnover data are higher than those previously reported. This discrepancy may possibly be attributed to the method of mathematical analysis.