Relations between daily energy expenditure and body fatness, physical fitness in primary school children using doubly labeled water method and accelerometer / 体力科学

The relationships between physical activity and childhood body size, low physical fitness epidemic are still unclear. The purpose of this study was to examine the relationship between energy expenditure estimated by doubly labeled water (DLW) method and body fatness, physical fitness in children, and the relationship between physical activity levels and percent time spent in activities. 30 healthy Japanese children (20 boys and 10 girls) participated in this study. The total energy expenditure (TEE) and % body fat were measured by the DLW method over a 6-day period. The physical activity-related energy expenditure (PAEE) was calculated as (TEE × 0.90) – basal metabolic rate (BMR). The physical activity level (PAL) was also calculated as TEE/BMR. The physical fitness tests (8 items) were applied to evaluate fitness, and scores of each test were calculated as overall physical fitness score. The TEE was 2009.8 ± 272.6 kcal/day, the PAEE was 558.4 ± 206.1 kcal/day and the PAL was 1.61 ± 0.18. TEE per weight and PAEE per weight (PAEE/wt) was significantly negatively correlated with % body fat (r = - 0.626; r = - 0.400, respectively). These results suggest that increasing energy expenditure is important for achieving adequate body size. The PAEE/wt was most strongly correlated with physical fitness score (r = 0.680). The PAL was associated with percent time spent of inactivity ( r = -0.506), light-moderate activity ( r = 0.450) and vigorous activity ( r = 0.545). It was suggested that physically active lifestyle would be necessary for childhood health.

WALKING 10,000 STEPS PER DAY IS EFFECTIVE TO IMPROVE CORONARY RISK FACTORS AMONG JAPANESES MIDDLE-AGED MEN / 体力科学

The purpose of this study is to investigate the effects of walking 10,000 steps per day on coronary risks including insulin resistance in Japanese. Twenty-one white-collar male workers (46.1±5.3 year-old) perform preventive lifestyle prescription. After 6 month, they showed improvements in BMI (p<0.05), VLDL (p<0.05), HDL cholesterol (p<0.001), and plasma insulin at 2 hr. post 75 g OGTT (p〈0.05). The participants increased their walk steps from 8,239±4,302 to 10,083±4,115 steps/day (p=0.09), and the increments of steps correlated with those of body mass index (r=−0.58, p<0.05), VLDL (r=−0.57, p<0.05), tryglycerides (r=−0.54, p<0.05), and blood glucose at 1 hr. post OGTT (r=−0.50, p<0.05) respectively. Especially 8 subjects with improved HOMA-R demonstrated more favorable modifications, and their gained 3,900 steps/day can meet the ACSM recommendation of physical activity. These outcomes could support a scientific aspect of anecdotal belief that walking 10,000 steps per day is effective to maintain one's optimum health.