Lactate uptake by inactive forearm during progressive leg exercise.

Eleven male subjects were studied during graded leg exercise from 60 to 270 W. Arterial and venous lactate concentrations were measured from the resting forearm during the exercise and recovery periods. Lactate concentration rose regularly during the work and declined slowly to basal levels after the exercise. The arteriovenous difference rapidly became positive during the exercise, indicating a net uptake of lactate by the nonexercising muscles. The uptake of lactate by the muscle correlated directly with the arterial concentration. After the 5th min of recovery, there was no longer any significant difference between arterial and venous lactate concentrations. It is concluded that 1) nonexercising muscles play a small role in the removal of lactate during exercise and 2) significant removal of lactate from the blood by nonexercising muscles stops soon after the cessation of exercise.