The purpose of this study was to compare the different exercise intensities and durations while using the same amount of energy during an exercise period to determine the effect on energy consumption and lactic acid concentrations during the recovery period. We enrolled 10 male college student volunteers from the National Taipei Teachers’ College (Age=23.4 ± 1.lyrs; Ht=173.9 ± 6.1cm; Wt=64.3 ± 11.8kg; VO2max=4O.5 ± 3. 5m1/kg/min). The subjects rid on the cycle ergometer at 50% and 70% VO2 max until the energy used was 170 Kcal, for continuous periods of 33 and 22 minutes, respectively. After exercise, the subjects’ energy consumption during the recovery period and blood lactic acid concentrations were measured. The results were as follows: 1) During the recovery period following cycle ergometer exercise at 50% VO2 max × 33 mm and 70% ‘O2 max × 22 mm the energy consumption values were 9.89 ± 2.89 and 15.03 ± 4.89 Kcal. The t- testing showed a significant difference (p＜.O5). 2) At 50% VO2 max × 33 mm and 70% VO2 max × 22 mm cycle ergometer exercise, at 0,5 and 30 minutes during the recovery period, the blood lactic acid concentrations were 3.38 ± 2.07 vs. 10.50 ± 4.13, 2.46 ± 1.20 vs. 9.43 ± 4.18, 1.74 ± 0.76 vs 3.98 ± 2.lommol/L. The t- tests showed a significant difference in all (p＜.O5). The results indicate that under similar energy expending conditions during an exercise period, the intensity of exercise is the main factor affecting energy consumption during the recovery period; elimination of lactic acid is a possible cause.
