Abstract

Maximal anaerobic capacity (maximal amount of energy released by anaerobic processes (Ean max, J/kg), has been evaluated from maximal increase of plasma lactate concentration (Lap) in 8 male subjects of different physical fitness submitted to supramaximal runs of various intensity performed until volitional exhaustion (tlim). The interindividual differences of tlim were reduced when exercise intensity was expressed by the anaerobic component of exercise defined as the difference between the overall energy requirement (E, W/kg) and maximal aerobic power (Eox max, W/kg). Within range intensity studied, Lap did not vary significantly as a function of E-Eox max. However, the performances achieved by the less fit subjects (group 1) remained lower than those achieved by the more athletic subjects (group 2). Mean Lap were significantly higher in group 2 than in group 1. The rate of increase of Lap, defined by the ratio Lap/t lim, was a linear function of E-Eox max. The energy equivalent of plasma lactate accumulation (beta), given by the reciprocal of the slope of the equation describing the relationship Lap/tlim=f (E-Eox max), amounts 56.8 J/kg when Lap is increased by 1 mmol/l. The energy released by anaerobic glycolysis was calculated by multiplying beta by mean Lap measured in the two groups. Assuming that the energy yielded by the anaerobic alactic processes amounts 260 J/kg, mean Ean max values in group 1 and 2 were found to be equal to 1040 (range: 910-1110) and 1240 (range: 1100-1330), respectively. Verf.-Referat (gekuerzt)