Abstract des Autors

Ten well-trained subjects performed a 120 km bicycle race and a 20 km run, one month apart. Plasma hematokrit, hemoglobin, glucose, free fatty acids, glycerol and lactate concentrations were measured one day prior to effort, 5-7 min after and one day after the race. Plasma lactate level after running was higher than after cycling (3.67 and 2.28 m mol/l, respectively). Foot race resulted in a significant increase in plasma glucose concentration reaching 8.64 mmol/l immediately after the race while after cycling no changes in plasma glucose levels were found. Plasma glycerol concentration following running was significantly lower than after cycling (0.28 mmol/l and 0.54 mmol/l, respectively). At the same time, prolonged cycling produced much higher free fatty acids concentrations than did the foot race (0.97 vs. 0.46 mmol/l, respectively). Despite pronounced differences in energy-yielding substrates concentrations after running and cyling, the elevations of plasma triacylglycerol levels were alike after both races. The role of lipoprotein lipases from different sources was discussed as a possible mechanism of an early increase in plasma triacylglycerol level following exercise. Verf.-Referat