Abstract

To delineate the possible age-related difference in blood lactate response during exercise and its relations to endurance performance, 34 male runners (aged 21 to 69 years) performed an incremental treadmill running test. There were no significant differences in training distance and relative body fat among younger runners (YR), middle-aged runners (MR), and older runners (OR). The 5-km run time slowed with age, but was ranked at relatively the same level in each age group. OR had a 23 and 12 lower maximal oxygen uptake (VO2max) and a 22 and 11 slower 5-km run time than YR and MR, respectively. However, mean VO2 corresponding to 4 mM of blood lactate (OBLA VO2) was the same among the groups when expressed as VO2max (YR; 84.3, MR; 85.9, OR; 85.9). Significant correlations were found between OBLA VO2 (ml/kg/min) and 5-km run time in each group (YR;r=-0.648,P<0.05; MR;r=0.658,P<0.01; OR;r=0.680,P<0.05). These results suggest that OR attain a given blood lactate level at almost similar VO2max to YR and MR and that OBLA VO2 in OR is useful for evaluating an endurance performance as well as in YR and in MR. Verf.-Referat