Institute for Sport and Physical Activity Research, University of Bedfordshire, Bedford, United Kingdom.
PLoS One. 2013;8(4):e61073. doi: 10.1371/journal.pone.0061073. Epub 2013 Apr 5.
Sedentary behaviour is a major risk factor for developing chronic diseases and is associated with low cardiorespiratory fitness in adults. It remains unclear how sedentary behaviour and different physical activity subcomponents are related to cardiorespiratory fitness in children. The purpose of this study was to assess how sedentary behaviour and different physical activity subcomponents are associated with 10-14 year-old schoolchildren's cardiorespiratory fitness.
135 schoolchildren (81 girls, 12±1 year) completed 7-day minute-by-minute habitual physical activity monitoring using triaxial accelerometers and undertook a maximal cardiorespiratory fitness test.
After controlling for sex, age, ethnicity, socioeconomic status and total wear time, light physical activity (1.5-2.9 METs) was negatively associated (β = -.24, p<.01) and hard physical activity (≥9 METs) positively associated (β = .45, p<.001) with cardiorespiratory fitness. Vigorous and hard physical activity were associated with cardiorespiratory fitness for boys (F = 5.64, p<.01) whereas light, moderate and hard physical activity were associated with physical fitness for girls (F = 10.23, p<.001). No association was found between sedentary time and cardiorespiratory fitness (r = -.13, p>.05). Sedentary to active transitions revealed little variability between cardiorespiratory fitness tertiles.
Hard physical activity (≥9 METs) holds greater potential for cardiorespiratory fitness compared to physical activity of lower intensities. There was no relationship between sedentary behaviour and cardiorespiratory fitness. These findings suggest that, for children, advice should focus on higher intensity physical activity and not sedentary behaviour as a means to maintain or improve cardiorespiratory fitness. Future research should explore longitudinal relationships between hard physical activity, cardiorespiratory fitness and health parameters.
久坐行为是导致慢性病的一个主要危险因素，与成年人的心肺功能较低有关。目前尚不清楚久坐行为和不同的身体活动亚组与儿童心肺功能之间的关系。本研究旨在评估久坐行为和不同的身体活动亚组与 10-14 岁学童心肺功能的关系。
135 名学童（81 名女生，12±1 岁）使用三轴加速度计完成了为期 7 天的分钟级日常身体活动监测，并进行了最大心肺功能测试。
在校正了性别、年龄、种族、社会经济地位和总佩戴时间后，低强度体力活动（1.5-2.9 METs）与心肺功能呈负相关（β=-0.24，p<.01），而高强度体力活动（≥9 METs）与心肺功能呈正相关（β=0.45，p<.001）。对于男孩，剧烈和高强度体力活动与心肺功能有关（F=5.64，p<.01），而对于女孩，轻、中、高强度体力活动与身体素质有关（F=10.23，p<.001）。久坐时间与心肺功能无相关性（r=-0.13，p>.05）。在心肺功能的三分位中，久坐向活动的转换差异较小。
与低强度的体力活动相比，高强度体力活动（≥9 METs）对心肺功能更有潜力。久坐行为与心肺功能之间没有关系。这些发现表明，对于儿童来说，建议应侧重于高强度的体力活动，而不是久坐行为，作为保持或改善心肺功能的手段。未来的研究应探讨高强度体力活动、心肺功能和健康参数之间的纵向关系。
