[Method for recovering and concentrating lactic acid during interval training]

Sixteen athletes were divided into 2 equal groups, A and B. Then, they were put through a series of repetitive trial exercises consisting in a sequence of 400 m races run to a sub-maximum speed (75% of maximum speed) and with pauses of a length of time equal to race time, and repeated to exhaustion, i.e., inability to keep up required speed. Recuperation in between races varied: Group A was completely passive, motionless; Group B was still going, albeit rather slowly. The parameters measured included blood concentration of lactic acid at rest and on completion of exercise and overall distance covered. At rest, there was a significant difference of lactatemia between the two groups. During the exercise, the distance run by Group B was longer (by 187.5 m) that that covered by Group A, though the difference was not significant (0.05 < P < 0.10), but his lactatemia was significantly much lower (P < 0.05). On average, the race speed and the time for recuperation which were alternatively measured were just the same for the two groups.