Anaerobic recovery in man.

The lactic acid (L.A.) concentration in blood after a 20 sec supramaximal exercise (2.5 times VO2max) has been measured in 4 subjects in the following experimental conditions: a) during the resting period following the supramaximal exercise (rest recovery) and b) during a 3 min exercise at VO2max immediately following the supramaximal effort (exercise recovery). The L.A. concentration in blood has been found to be consistently higher (on the average by 16.9 mg%) in case (b). Since in such condition it may be reasonably assumed that the oxygen taken up by the subject is completely utilized for the exercise, the increase of blood lactate is considered evidence for the occurrence of anaerobic recovery, i.e. of a partial re-synthesis of the high energy phosphate stores of the muscle (GP = ATP + PC) depleted during the supramaximal effort, at the expense of anaerobic glycolysis. From the increase in blood L.A. concentration during the anaerobic recovery period, the amount of L.A. produced has been estimated together with the amount of GP resynthesized. The latter corresponds to 4 to 7 mMoles/kg of muscle, i.e. to about 25% of the average GP concentration in resting human muscle. The finalistic implication of this mechanism is the prompt restoration of the potential maximal power of the muscle even in the absence of O2.