PLASMA LACTATE ACCUMULATION AND DISTANCE RUNNING PERFORMANCE (REPRINTED FROM MEDICINE AND SCIENCE IN SPORTS, VOL 11, PG 338-344, 1979)

Laboratory and field assessments were made on eighteen male distance r unners. Performance data were obtained for distances of 3.2, 9.7, 15, 19.3 km (n = 18) and the marathon (n = 13). Muscle fiber composition e xpressed as percent of slow twitch fibers (%ST), maximal oxygen consum ption (VO2max), running economy (VO2 for a treadmill velocity of 268 m /min), and the VO2 and treadmill velocity corresponding to the onset o f plasma lactate accumulation (OPLA) were determined for each subject. %ST (R-.47), VO2max (r greater-than-or-equal-to .83), running economy (r greater-than-or-equal-to .49), VO2 in ml/kg min corresponding to t he OPLA (r greater-than-or-equal-to .91) and the treadmill velocity co rresponding to the OPLA (r greater-than-or-equal-to .91) were signific antly (p<.05) related to performance at all distances. Multiple regres sion analysis showed that the treadmill velocity corresponding to the OPLA was most closely related to performance and the addition of other factors did not significantly raise the multiple R values suggesting that these other variables may interact with the purpose of keeping pl asma lactates low during distance races. The slowest and fastest marat honers ran their marathons 7 and 3 m/min faster than their treadmill v elocities corresponding to their OPLA which indicates that this relati onship is independent of the competitive level of the runner. Runners appear to set a race pace which allows the utilization of the largest possible VO2 which just avoids the exponential rise in plasma lactate.