One-year Changes in Activity and in Inactivity Objectively Measured Among Overweight and Obese Children

Participation in physical activity (PA) during childhood can help to reduce the onset of risk factors associated with ill health. Seasonal influences play a large role in determining PA behaviors. Lack of information about overweight (OW) and obese (OB) children PA and sedentary (SED) behaviors, evaluated during a whole year, has made it difficult to assess appropriate interventions. PURPOSE: The aim of this study was to objectively measure PA behavior in a sample of 6 to 14 yr-old children in order to investigate seasonal and weekly differences in PA and SED habits. METHODS: 18 OW and OB children (OW (n=8): age 10,8±1,2 yr; BMI, 21,9±1,4 kg/m2; OB (n=10): age 10±2,1 yr; BMI 25,6±3,2 kg/m2) were monitored during a whole week 4 times in a year with a Actiheart (AH) monitor (Cambridge Neurotechnology, UK), inferring time spent in sedentary (SED, <1.5 METs) or moderate to vigorous (MVPA, >3 METs) intensity. Data presented provide a minimum of four days of 10-h valid recording per week (at least 1 weekend day is included). A Repeated measure ANOVA was used to analyse data and significance was set at p<0,05. RESULTS: A non significant seasonal difference was detected for time spent in MVPA (spring 129,7±82,4; summer 106,7±76,9; fall 93,5±72; winter 82,7±60,3 min/day) causing, on the contrary, a significant seasonal difference in activity energy expenditure (AEE: spring 660,5±188,3; summer 540,8±132,1; fall 538,9±152,5; winter 482,2±136,2 kcal/day; p<0,05). A significant seasonal difference was found in SED behavior (spring 436,9±95,6; summer 389,7±81,2; fall 479,2±93,3; winter 473,8±80,1 min/day; p<0,05). No significant differences appeared between weekly and weekend days (MVPA: weekdays 100,7±70,1; weekend 110,1±87,8; SED: weekdays 460,6±94,8; weekend 431,6±118,9 min/day). Besides, OW appeared to be more active than OB children (MVPA: OW 122,8±86,2; OB 87,3±60,8 min/day, p<0,05). CONCLUSIONS: The main finding of this study is that AH data, taking activity into account (without loosing water sports or activity), indicate that for OW and OB children activity levels are highest in spring, drop in summer and reach the lowest point in winter. Besides, children do not result to be more active on weekly days than during the weekends as reported by some authors. Kristensen PL et al. Scand J Med Sci Sports. 2008 Jun;18(3):298-308.