Abstract

This investigation was undertaken to determine whether human skeletal muscle buffer capacity (BCm) is affected by training. Eight untrained males participated in 8 weeks of sprint training on bicycle ergometers. Muscle biopsy samples were taken before and at several times following an incremental bicycle ergometer test. The subjects were tested before (PRE) and following (POST) the training period. Seven endurance-trained cyclists (ET) were also tested. Biopsy samples were analyzed for lactate concentration (HLam), homogenate pH (pHm), and creatine phosphate concentration. BCm was calculated from the change in HLam and pHm observed from rest to exhaustion. There was no significant difference in resting HLam or resting pHm among the groups. There was a significant difference in HLam at exhaustion between PRE (21.41 +/- 1.65 mmol/kg), POST (25.61 +/- 2.38 mmol/kg), and ET (11.16 +/- 0.31 mmol/kg) but no significant difference in pHm at exhaustion between PRE and POST. pHm at exhaustion for the ET group was significantly higher. A significant difference between PRE and POST BCm was found (PRE: 44.68 +/- 3.03 S1; POST: 61.04 +/ - 4.11 S1) while ET BCm (47.21 +/- 7.26 S1) was not significantly different from PRE. These data indicate that muscle buffer capacity is increased with highly intense sprint training but provide no evidence to suggest that muscle buffer capacity is affected by endurance training. Verf.-Referat