Computer games do not afford much physical activity and hence do not require significant energy expenditure, which can contribute to the prevalence of a sedentary lifestyle. A "hand exerciser" handgrip can help strengthen hand and forearm muscles through a simple spring mechanism. We are presenting the mousegrip, an exertion interface to control computer games while simultaneously exercising hand and arm muscles based on a handgrip device. Unlike conventional vision or accelerometer-based exertion interface devices, the mousegrip is very low-cost and supports cheap force-feedback through a simple spring mechanism. Due to its low cost, its mobile form factor and compatibility to existing mouse drivers, the mousegrip can augment traditional mouse interactions with an exertion activity to make exercising more enjoyable, and gameplay healthier. It provides a familiar affordance of interaction and supports increased calorie expenditure, hence contributing to people's fitness. We hope to encourage other researchers to incorporate exertion activity into their interfaces in order to support a healthy lifestyle. Read more...

Background and Objective: Waist circumference (W) has been shown to be a good predictor of cardiovascular risk. The aim of this study was to investigate whether physical activity (PA) is related to W in adolescents as previously shown in adults. Design and Subjects: Cross-sectional population-based survey of 2714 12-y-old adolescents from the eastern part of France. MEASUREMENTS: Body mass index (BMI) and W were measured. Structured PA, active commuting to and from school and sedentary activities (SED), for example television viewing, computer/video games and reading and different potential confounders (dietary habits, parental overweight, family annual income tax and educational level) were assessed by a questionnaire. Results: The adolescents had a mean BMI of 19.0+/-3.4 kg/m(2), and 20.2% of them were overweight, with no gender difference. Boys had a greater W than girls (67.6+/-9.1 vs 65.7+/-8.9 cm, P<0.0001). In all, 42% of the girls and 25% of the boys did not practice any structured PA outside school and less than 40% of the adolescents commuted actively to school more than 20 min/day. About one-third of the adolescents devoted more than 2 h/day to SED. In univariate analyses, BMI was negatively associated with structured PA but significantly only for girls (P<0.01) and positively associated with SED for both genders (P<0.0001 for girls, P<0.01 for boys). W was negatively associated with structured PA and positively associated with SED both in girls (P<0.0001 and P=0.03, respectively) and boys (P<0.01 and P=0.08, respectively). Multiple general linear models show that SED is associated with BMI, independently of structured PA, in both genders. On the other hand, structured PA was inversely associated with W, independently of SED. The inverse relation between structured PA and W persisted after additional adjustment on BMI, with a greater effect of PA for the adolescents with higher BMI. Conclusions: In 12-y-old adolescents, structured PA is inversely associated with W, an indicator of total adiposity but also more specifically of abdominal fat. This suggests that PA may have a beneficial effect on youth metabolic and cardiovascular risks, in particular in the presence of overweight. Read more...

Objective: To determine whether there is a relationship between the time adolescents spend in physical activity and time they spend in different sedentary pursuits: watching television, playing video games, working on computers, doing homework, and reading, taking into account the effect of part-time work on students' residual time. Design: Cross-sectional cohort design. Participants and Setting: Seven hundred forty-three high school students from 2 inner-city public schools and 1 private school. Methods: Students completed a self-administered questionnaire that addressed time spent in physical activity, time spent in sedentary pursuits, musculoskeletal pain, and psychosocial issues and were also measured for height and weight. Main Outcome Measure: Level of physical activity (low, moderate, high). Results: There were more girls than boys in the low and moderate physical activity groups and more boys than girls in the high activity group. Ordinal logistic regression showed that increased time spent in "productive sedentary behavior" (reading or doing homework and working on computers) was associated with increased physical activity (odds ratio, 1.7-1 95% confidence interval, 1.2-2.4), as was time spent working (odds ratio, 13;95%confidence interval, 1.2-1.4). Time spent watching television and playing video games was not associated with decreased physical activity. Conclusions: Physical activity was not inversely associated with watching television or playing video games, but was positively associated with productive sedentary behavior and part-time work. Some students appear capable of managing their time better than others. Future studies should explore the ability of students to manage their time and also determine what characteristics are conducive to better time management. Read more...