Very few studies have reported an independent association of the physical activity-related indices with the psychological stress reaction. The present study therefore investigated the association of fitness and screentime as one of the indices of sedentary behavior with the four types of psychological stress reactions and the number of days absent from school for 249 children at a local public school and a metropolitan private school while considering confounding factors. No significant difference was observed in the fitness level of both schools; however, the rate of obesity, the screentime and the level of all psychological stress reactions were significantly worse in the public school. Further, significant differences and trends among the groups classified by fitness level were recognized in the rates of participation in after school activities, feeling of powerlessness and days of absence per year. In addition, the odds ratio of the screentime for depressive and anxiety symptoms was 1.004 (95%CI: 1.000-1.007, p=0.039), while the odds of the fitness level for high feeling of powerlessness and more than five days of absence were 1.582 (95%CI: 1.045-2.396, p=0.030) and 1.434 (95%CI: 1.045-2.396, p=0.015), respectively, after adjusting for the school type, differences in lifestyle and participation in after school activities. In conclusion, the fitness level and the screentime were associated with high psychological stress reactions and the days of absence, independent of the above-mentioned adjusting factors among the children in the present study. Prospective and interventional studies to verify these results are needed.

Resting O₂ consumption following exercise at ventilatory threshold (VT) intensity was measured in order to investigate the magnitude and duration of excess post-exercise O₂ consumption in untrained men. Nine untrained males (mean age 24.8±1.5 years) exercised for one hour at VT intensity (58.2±1.7% of VO₂max) on a cycle ergometer, and then rested for 12 h sitting in a comfortable armchair (post-exercise) . On a separate day the subjects rested for 12 h but without preceding exercise (non-exercise) . O₂ uptake (VO₂) and heart rate (HR) were measured for 5 min every 30 min throughout the 12 h rest period and again at 24 h following the exercise. High-carbohydrate meals (carbohydrate 112.8±5.1 g, protein 9.7±0.4 g, fat 1.8±0.1 g) were given to the subjects at 2, 7 and 12 h following the exercise. The total energy intake per day was 1591.7±71.8 kcal. V0₂ and HR were significantly higher, and respiratory quotient (RQ) was significantly lower at most of the measured time-points for post-exercise than for non-exercise. Total energy consumption for the 12 h rest period was 957.3±25.5 kcal for post-exercise and 840.3±15.8 kcal for non-exercise, respectively. After 24 h no difference was observed in VO₂ and HR between post-exercise and non-exercise, but RQ was significantly lower in the former than in the latter (0.86±0.05 vs. 0.90±0.04, p<0.05) . These results suggest that exercise for one hour at VT intensity enhances resting VO₂ for at least 12 h, and elevates the rate of fat utilization for at least 24 h.

The purpose of the present study was to investigate the baseline characteristics related to the participation status in a longitudinal epidemiological study for the elderly. Nine hundred twenty-six self-supporting older adults lived in a local city located southwest in Japan were classified into the following 3 groups; non-participants (NP, n=170), participants for the baseline measurements (PB, n=278), and participants for both the baseline and follow-up measurements after two-years (PBF, n=478). The basic attributes including socioeconomic status, depressive symptoms, cognitive function, sleep quality, fitness, objectively- measured physical activity, habitual behavior, psychosocial characteristics and functional problems in daily life were assessed. Regarding the NP group, data were collected by questionnaire or home visits. According to the results of a multinomial logistic regression analysis adjusted for age, sex and years of education, significant odds ratios which indicate a poor status in most of the assessment items were observed in both the NP and PB groups in comparison to the PBF group. We concluded that sex (female), a higher age, fewer years of education, a cognitive function decline, depressive symptoms, a low fitness level, physical activity and daily living function, and poor psychosocial backgrounds were related to the non-participation and dropouts. These results should be considered in a longitudinal data analysis of the present study, as well as in the design setting of epidemiological studies dealing with physical activity indexes and care risk factors. Furthermore, these findings are also considered to be useful as basic data for such care prevention activities in the community.

This prospective study was designed to clarify the association between the incidence of falls and physical fitness in healthy community-dwelling elderly people without history of fall-related injuries within 1-5 years before the baseline assessment. Six hundred and one elderly subjects aged 60-79 years who lived independently participated in baseline assessments from March 2002 to March 2004, and were followed up for one year to detect falling. Demographic items (age and sex), chronic disease, self-rated health, difficulty in performing any activity, tendency to stay at home, body mass index (BMI), %vital capacity, handgrip and knee extension strength, stepping rate, one-leg standing with eyes opened, trunk flexion at sitting position, maximum walking speed, instrumental activity of daily living (IADL), and General Health Questionnaire (GHQ30) were assessed at baseline. Four hundred and eighty-one participants (80.0%) completed the 1-year follow-up.The fall incidence was 13.1%. In men, fallers had lower BMI and decreased maximum walking speed, however, neither showed significant odds ratio (OR) for fall. In women, fallers had lower knee extension strength and the ratio of weak side to strong side (WS/SS ratio) in knee extension strength compared to non-fallers. The age-adjusted OR for fallers in the lowest quartile (knee extension strength＜0.681kg/BW) was 3.07 (95%CI : 1.02-9.22) compared to highest quartile (＞0.980 kg/BW), while the multiple-adjusted OR was not significant (OR＝2.88, 95%CI : 0.94-8.79). However, the multiple-adjusted OR for fallers in the lowest quartile of the WS/SS ratio in knee extension strength (＜0.771) was 4.49 (95%CI : 1.40-14.37) compared to highest quartile (＞0.947).As for conclusion, without history of fall-related injuries, only a weak association between falls and physical fitness was observed in men. In women, the unbalanced knee extension strength was associated with falls. The WS/SS ratio in knee extension strength might be a key factor in predicting falls in women.