ASSESSMENT OF LACTATE THRESHOLD DURING ARM EXERCISE N COMPETITIVE SWIMMERS1523

The purpose of this study was to evaluate physiological characteristics in competitive swimmers by assessing lactate threshold (LT) during arm cranking. Nine collegiate competitive swimmers (S) completed an incremental exercise test (AC) using an arm crank ergometer until exhaustion. Additionally, 11 endurance trained- (runners and cyclists; E) and 9 untrained- (U) individuals underwent the same exercise test for the purpose of comparison to the swimmers. Blood samples were taken from a dorsal vein of the foot to determine blood lactate levels during AC and 20-min recovery. Maximal power output(POmax) was significantly greater in S than in E and U (128.3±18.8 vs. 85.1±14.5 and 64.9±10.8watts, respectively; p<0.01). Also, a greater LT was observed in S compared to that in E and U (51.2±12.5 vs. 28.6±10.0 and 26.0±15.9%POmax, respectively; p<0.01). POmax in E significantly differed from that in U (p<0.01), whereas no significant difference in LT was observed between E and U. During recovery from AC, a change in blood lactate levels in S was prominent compared to that in E and U. The peak blood lactate level during recovery was attained significantly more quickly in S than in E and U, and in E than in U (2.0±1.1, 3.7±1.4; and 6.6±1.0min, respectively; p<0.05). The peak blood lactate value was significantly lower in S than in E and U, and in E than in U (3.8±0.7, 5.8±1.0, and 7.5±2.0mmol/l, respectively; p<0.01). In conclusion, the greater LT during arm exercise in S might be attributed to their specific arm training. The lower peak blood lactate level and faster attainment of the peak level after maximal arm exercise in S suggest their enhanced lactate uptake and/or distribution. Endurance training such as running and cycling did not appear to improve LT during arm exercise.