The purpose of this study was to examine the association of screen viewing time (SVT) and study time (ST) with physical fitness among second-year high school students. This cross-sectional study was carried out including 678 (boys: n = 322) students enrolled from 2011 to 2013. Physical fitness measurements included muscular fitness, explosive power and endurance performance. Muscular fitness and explosive power were evaluated by grip strength and standing broad jump test, respectively. Endurance performance was evaluated by endurance running speed of 1500 meters (in boys) or 1000 meters (in girls) running. SVT, ST and other lifestyle behaviors were obtained by a self-reported questionnaire. Analysis of covariance was used to examine the association of SVT and ST with grip strength, standing broad jump distance and endurance running speed. After adjustment for potential confounders, longer SVT was associated with poorer endurance running speed in both boys and girls, (p for trend < 0.01). Longer SVT was also associated with lower standing broad jump distance in boys (p for trend = 0.007) and grip strength in girls (p for trend = 0.005). In boys, longer ST was also associated with lower grip strength after adjustment for potential confounders (p for trend = 0.007). In conclusion, these results suggest that differences between SVT and ST may have different effects on physical fitness data 3-year after the earthquake disaster. Further studies are necessary to confirm the findings of this study.

Coffee administration has been shown to increase maximum voluntary contraction and muscular endurance. However, no study has addressed the association between daily consumption of coffee with muscular function. This cross sectional study aimed to investigate the association between frequency of coffee consumption (CC) in daily life and muscle strength among a population of working adult men. This cross sectional study included men (n = 516, mean age: 47.1) who participated in an annual health examination conducted in Sendai. The monthly frequency of coffee consumed was reported by a brief-type self-administered dietary history questionnaire. Leg extension power (LEP) was measured as an index of muscle strength. Subjects were divided into tertile levels according to CC. Analysis of covariance was used to examine the relation between the tertile levels of CC and LEP. After adjustment for potential confounders (including all lifestyle factors), the adjusted means (95% confidence interval) of LEP across the tertiles of CC were 17.4 (16.6 - 18.1) for the lowest tertile, 17.9 (17.4 - 18.5) for the mid tertile, and 18.9 (18.3 - 19.5) for the highest tertile (p for trend = 0.007). Higher frequency of monthly coffee consumption was associated with higher muscle strength.

Objective To evaluate the reliability and validity of extended reach lateral method by assessing the ability of lateral balance control in elderly people,and to provide a simple method to assess the ability of lateral balance control in order to provide a reasonable basis for fall prevention in elderly people.Methods 83 elderly people aged (77.3 ± 4.7) years were included in this study.Using lateral displacement of center of foot pressure as the criterion,the reliability and validity of extended reach lateral method was evaluated.Results Left and right sides of lateral reach were (14.7±0.4) cmand (14.9±0.3) cm.Left and right sides of center of foot pressure excursion were (8.5±1.9) cm and (8.5±1.5) cm.Lateral reach was significantly correlated with the center of foot pressure excursion (r=0.70,P＜0.001).Lateral reach had a high intraclass correlation coefficient (r=0.97,P＜0.05).Lateral reach was significantly correlated with age and height (r=-0.23 and 0.28,both P＜0.05),while it had no correlations with the foot length,foot pitch and handedness (all P＞0.05).Conclusions Lateral reach has a high reliability and validity to assess the ability of lateral balance control in elderly people,which is easy to be applicated and popularized.

Measuring the bioelectrical impedance (BI) is a simple and non-invasive method for estimating body fat or muscle mass. However, body impedance is affected by variations in the distribution of body fluid without reference to actual body fat or muscle mass. Twenty healthy college students (10 males, 10 females; mean age 21.0±2.3 years) participated in the study. Their mean body mass index was 20.7±2.6 kg/m². Bipolar electrodes were place on all extremities, and InBody 3.0^TM (Biospace Co., Ltd., Seoul, Korea) was used to measure bioelectrical impedance. Each subject remained in a supine position on a comfortable bed between 07:00 and 12:00 except for excretion and measurement of BI. BI was measured hourly using frequencies ranging from 5 to 500 kHz. The subjects refrained from eating, drinking and exercising between 07:00 and 12:00 during the first week of measurements, and drank 6.7 ml/kg of water at 07:00 after the first measurement of BI during a subsequent week of measurements. Bioelectrical impedance was higher in female subjects in all body segments and conditions (p<0.01). BI in the right arm was lower than that in the left in all participants (p<0.001). The difference between the highest and lowest BI among six measurements was largest in the upper extremities, followed by the lower extremities. Differences in the coefficient of variation CV values of the right arm of both females and males at 50, 250, and 500 kHz during fasting were significantly smaller than after drinking water. Hydration had no effect on the differences in the CV values of the body trunk and lower extremity BI or BI at lower frequencies. BI indicates the possibility of remarkable decrease in variation in the upper extremity BI at higher frequencies by taking 6.7 ml/kg of water at get up and enables minimizing the estimate error of body fat percentage.

[Purpose] To investigate the relation between isotonic leg extension strength (ILES) and the prevalence of metabolic syndrome (MS) in Japanese male adults.[Methods] This cross-sectional study included 395 Japanese men. Metabolic syndrome was determined according to the criteria of International Diabetes Federation (IDF), Japan Society for the Study of Obesity (JASSO), or National Cholesterol Education Program's Adults Treatment Panel III (NCEP-ATPIII). Muscular strength was measured on a horizontal dynamometer. Subjects were divided into tertile levels according to ILES (watts/kg). Multiple logistic regression analysis was used to examine the relation between ILES levels and the prevalence of MS.[Results] The prevalence of MS were 14.4% (IDF), 17.0%(JASSO), and 20.0% (NCEP-ATPIII). After adjustment for confounding factors, the odd's ratios (95% confidence interval) of MS (IDF) compared with the lowest ILES level were 0.90 (0.48-1.68) and 0.31 (0.13-0.64) in the middle and high levels of ILES (p for trend=0.03). The association between the level of ILES and the prevalence of MS by JASSO and NCEP-ATPIIIcriteria were similar.[Conclusion] The prevalence of MS was associated with the level of ILES.

Objective To investigate the association between physical activity volume and medical care cost in elderly persons aged 70 years and over in Crane Valley, Sendal, Japan. Methods A total of 494 community-dwelling Japanese elderly persons living in residential area of Sendai City in northern Japan completed a self-administered questionnaire that included questions on physical activity. We ascertained total medical care costs through computerized linkage with claims lodged between November 2002 and December 2004 from the Miyagi National Health Insurance Association.Results After multivariate adjustment for potential confounders, the average monthly medical costs of hospitalization, hospital days, outpatient medical expenses, out-patient numbers and the total medical expenses in grade Ⅰ exercise volume group were (196.7±72.1) U.S. dollars, (0. 7±0.3) d, (308. 7±54.4) U.S. dollars, (6.2±1.1) times and (506. 95±94. 2) U.S. dollars; in grade Ⅱ exercise volume group were (139. 8±72.1) U.S. dollars, (0.5±0. 3) d, (295.3±54.6) U.S.dollars, (6.1±1.1) times and (437.8±94.5) U.S. dollars; in grade Ⅲ exercise volume group were (134.1±72.5) U.S. dollars, (0.4±0.3) d, (278.8±54.9) U.S. dollars, (5.8±1.1) times and (418. 1±95.0) U.S. dollars. With the increase in physical activity, there were significant differences between the medical costs of hospitalization and total medical expenses (F=5.85 and 8.11, both P=0.01). Conclusions This prospective study indicates that a higher volume of physical activity is associated with lower medical care costs among Japanese elderly persons.

Because falls occur not only in the forward direction, but also in the lateral direction, lateral postural instability may contribute to the risk of fall accidents of community-dwelling elderly adults. The purpose of this study was to determine the relationship between lateral reach (LR) and the lateral excursion of the center of pressure (COP), and their association with self-reported fall incidences.The COP stability limits in LR were recorded using a force plate for 83 community-dwelling elderly people aged 70 years and over with reduced physical functions, who answered a questionnaire for fall incidences in the previous six months. LR was significantly correlated with bi-directional COP stability limits (r=0.57～0.70, p<0.0001). The sum of bi-directional LR was significantly correlated with that of bi-directional COP stability limits (r=0.62, p<0.0001). In the full sample (n=83), people whose LR was equal to or less than 30.1 cm are about 4 times more likely to fall (odds ratio [OR] of fall incidence = 4.15, 95% confidence interval [CI] = 1.31～15.95) than people whose LR was more than 30.1 cm. After adjustments for age, sex, and height, the OR =4.08, 95 %CI =1.11～18.05,(p<0.05).The LR test was found to be a simple and easy evaluation method for lateral balance. LR is associated with fall incidence. Thus, the LR test may be a useful clinical measure for detecting the fall risk of elderly adults.

The purpose of this study was to determine whether improved physical fitness through a new exercise program intervention including elements of Tai Chi Chuan and Kung Fu gymnastics among elderly people who have lower physical. Eighty older adults with less physical strength aged 71-89 (mean age±SD=77.3±3.9), recruited from Tsurugaya area of Sendai, participated in a 3-month randomized controlled trial, with allocation to a new exercise program or well-accepted exercise program control. Physical performance measures included the timed up and go test (TUGT), the functional reach test, a 6 min continuous walking test, and the sit-and-reach test were conducted before and after the intervention. Data were analyzed through on-treatment-analysis of variance. After training, although no significant between-groups differences were observed for all the measures, TUGT, which is recommended as a simple screening tool to identify those at risk of falling was improved in both groups following the intervention (P<0.05). The findings revealed that the new exercise program including Tai Chi Chuan and Kung Fu gymnastics element could improve physical fitness to a similar level as the well-accepted exercise program.