RESUMEN
We have determined the plasma 8-hydroxy-deoxyguanosine (8-OHdG) levels during endurance exercise. Eight untrained male subjects completed a 10-km run. Plasma 8-OHdG, total coenzyme Q10 (CoQ10), ubiquinol, and thiobarbituric acid (TBA) concentrations were measured after exercise. Plasma 8-OHdG concentrations significantly decreased immediately after (0.21±0.13 ng/ml, p<0.01) and 1 hr after (0.23±0.09 ng/ml, p<0.05) the run compared to the resting values (0.36±0.09 ng/ml). Both plasma CoQ10 and ubiquinol concentrations significantly increased (p<0.05) immediately after the run compared to the resting values. On the other hand, plasma TBA concentrations did not change significantly at any point after the run. These results suggest that, during and after submaximal endurance exercise in this study, an augmented antioxidant defence system such as CoQ10 might thus play a role in the decrease of 8-OHdG in the plasma, and that exercise might stimulate the repair of oxidative damage to DNA.
RESUMEN
The relationship between daily physical activity and physical fitness in female college students was investigated. Sixteen female college students who regularly took exercise two or three days per week were selected for the active group. Seventeen female college students who seldom took exercise and had not taken part in any kinds of sports activities while at high school were selected for the inactive group. Physical fitness tests and incremental loading maximal cycling exercise tests were undertaken by all subjects. Gas expired during the cycling exercise was collected in a Douglas bag, and ventilation, oxygen uptake and respiratory quotient were measured for each exercise load and in the last few minutes of the exercise test. Electrocardiographic data were also obtained during the test. Heart rate during daily activities in each subject was recorded continuously throughout the day using a heart rate recorder. Daily energy expenditure was estimated from the continuous recordings of heart rate using the linear relationship between heart rate and oxygen consumption obtained in the maximum incremental exercise test. Mean number of strides taken by each subject during da ily activities was also obtained using a pedometer for one week.<BR>The results can be summarized as follows.<BR>1) Maximal oxygen uptake and total score in the physical fitness test averaged 37.8 m<I>l</I>/ kg/min and 27.8 points, and 30.1 m<I>l</I>/kg/min and 22.5 points for the active and inactive group, respectively. The inter-group differences in these parameters were significant.<BR>2) The mean values of daily energy expenditure and strides taken during daily activity were about 2400 kcal/day and 14000 strides/day, and 1800 kcal/day and 7000 strides/day for the active and inactive group, respectively. The differences between the groups for these two values were also significant.<BR>3) The difference in daily energy expenditure between the two groups was 580 kcal and the difference in total strides per day was 7000 strides.<BR>4) These results indicate that both daily physical activity and physical fitness in the inactive group were lower than those in the active group. Furthermore, it was proved that the level of physical fitness in female college students is closely related to their daily physical activity.