Reduction of exercise capacity in children from summer to winter is associated with lower sporting activity: a serial study

Abstract

Background: Declining activity in children over the past decades is thought to be one of the main risk factors for an early development of exercise intolerance and obesity. Taking this background into account, this prospective study investigated the seasonal change of children's physical activity and its association with objective measures of exercise capacity. Methods: A total of 96 children from two schools in Munich (42 girls, age 12.4 ± 0.8 y) underwent a cardiopulmonary exercise test (CPET) and an assessment of their daily activities (school sport, club sport, leisure sport) twice. Baseline testing was conducted in summer 2011. Follow-up examination was performed during winter 2012. results: From summer to winter, self-reported sporting activity decreased from 10.6 ± 4.1 to 8.5 ± 4.3 h/wk (P < 0.001) as school sport (P < 0.001) and leisure sport activities (P = 0.002) decreased, but the activity associated with club sport did not (P = 0.700). In parallel, peak oxygen uptake (VO 2 ) declined from 102.0 ± 17.5 to 96.9 ± 17.9 % of predicted (P < 0.001). This decline in VO 2 was associated with a reduction in overall sporting activity (r = 0.234; P < 0.032). conclusion: Enhancing sporting activity in children during winter might be important to maintaining their exercise capacity. P hysical activity is important for metabolic and mental health in adults as well as in children (1-7). Schoolchildren should participate on a daily basis in 60 min or more of moderate to vigorous physical activity that is developmentally appropriate, enjoyable, and involves a variety of activities (4,6,8). Unfortunately, the activity levels of children (and also adults) are decreasing in our Western industrialized countries (9-11), and more than 60% of the world's population does not engage in enough physical activity (6,11). As if that were not enough, a study suggests (1) that those recommendations for daily activity were too low to reduce the clustered cardiovascular risk of children.Regarding the seasonal change in daily activity, fewer data are available. In a recent review article (12) on accelerometerdetermined physical activity data in children, only four studies (13-16) with a longitudinal design were identified. All except one (14-16) reported on significant lower activity pattern during winter. Those findings were supported in other review articles (12,17). However, whether that decrease in activity during winter was also associated with a reduction of exercise performance was not examined in the mentioned studies.Therefore, this study aimed to compare the seasonal change in activity levels in children with their objective measured exercise performance obtained with a cardiopulmonary exercise test (CPET). Exercise capacity is positively associated with daily activity (5,18,19), and peak oxygen uptake (VO 2 ), the gold standard measurement of exercise capacity, has also been shown to be of predictive value in apparently healthy adults (20), as well as in patients with several diseases (20-23). (Table 1), children reported t...

Body Weight and Not Exercise Capacity Determines Central Systolic Blood Pressure, a Surrogate for Arterial Stiffness, in Children and Adolescents

“…From April 2011 to August 2014, 320 healthy children and adolescents younger than 20 years (252 male, 14.0±2.1 years) were prospectively investigated for their anthropometric, hemodynamic, and cardiopulmonary parameters. The study cohort consisted of individuals evaluated in a school project and healthy patients assessed in our department. All patients underwent the same measurement of their anthropometric, hemodynamic, and cardiopulmonary parameters.…”