Marques Adilson, Santos Rute, Ekelund Ulf, Sardinha Luís B
1Centro de Estudos de Educação e Promoção da Saúde, CIPER, Fac Motricidade Humana, Univ Lisboa, Cruz-Quebrada, PORTUGAL; 2Maia Institute of Higher Education (CIDAF), Maia, PORTUGAL; 3Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, PORTUGAL; 4Department of Sport Medicine, Norwegian School of Sport Sciences, NORWAY; 5MRC Epidemiology Unit, University of Cambridge, Cambridge, UNITED KINGDOM; and 6Exercise and Health Laboratory, CIPER, Fac Motricidade Humana, Univ Lisboa, Cruz-Quebrada, PORTUGAL.
Med Sci Sports Exerc. 2015 Mar;47(3):575-80. doi: 10.1249/MSS.0000000000000426.
This study aimed to examine the associations between objectively measured physical activity (PA), sedentary time, and health-related fitness and to investigate the combined association of PA and sedentary time on health-related fitness in youths.
PA and sedentary time were assessed with accelerometers in 2506 youths age 10-18 yr (M(age) = 13.2 ± 2.3). Participants were classified as active (≥60 min·d(-1) of moderate-to-vigorous physical activity (MVPA)) versus inactive (<60 min·d(-1) of MVPA) and as "low sedentary" versus "high sedentary" (according to the median value of sedentary time per day) and thereafter grouped as active/low sedentary, active/high sedentary, inactive/low sedentary, and inactive/high sedentary. Five physical fitness tests (body mass index, push-ups, curl-ups, sit and reach, and the Progressive Aerobic Cardiovascular Endurance Run test) were assessed with FITNESSGRAM, and participants were categorized as being in the healthy fitness zone (HFZ) versus the unhealthy fitness zone. A fitness composite score was calculated using the individual fitness test z-score. Regression models were used to examine the relation between PA, sedentary time, and physical fitness.
Time spent in MVPA (min·d(-1)) (β = 0.002, P < 0.001) was significantly associated with fitness score independent of sedentary time. Sedentary time was not associated with physical fitness independent of MVPA. Compared with the inactive/high sedentary group (referent), being categorized as active/low sedentary was associated with increased likelihood of being in the HFZ for sit and reach (odds ratio, 2.55; 95% confidence interval, 1.96-3.32) and having a higher fitness composite score (odds ratio, 1.38; 95% confidence interval, 1.13-1.69).
Time in MVPA was associated with better physical fitness independent of sedentary time. Participants classified as active/low sedentary had higher odds of being in the HFZ, for flexibility, and to have a better fitness composite score. These findings suggest that time in MVPA contributes to better physical fitness in youths.
本研究旨在探讨客观测量的身体活动（PA）、久坐时间与健康相关体能之间的关联，并调查PA和久坐时间对青少年健康相关体能的综合影响。
使用加速度计对2506名10 - 18岁的青少年（平均年龄 = 13.2 ± 2.3岁）的PA和久坐时间进行评估。参与者被分为活跃组（每天中等至剧烈身体活动（MVPA）≥60分钟）和不活跃组（每天MVPA<60分钟），以及“低久坐”组和“高久坐”组（根据每天久坐时间的中位数），然后分为活跃/低久坐、活跃/高久坐、不活跃/低久坐和不活跃/高久坐组。使用FITNESSGRAM评估五项体能测试（体重指数、俯卧撑、仰卧起坐、坐位体前屈和渐进性有氧心血管耐力跑测试），参与者被分类为处于健康体能区（HFZ）和非健康体能区。使用个体体能测试z分数计算体能综合得分。使用回归模型来研究PA、久坐时间和体能之间的关系。
独立于久坐时间，MVPA所花费的时间（分钟·天）（β = 0.002，P < 0.001）与体能得分显著相关。独立于MVPA，久坐时间与体能无关。与不活跃/高久坐组（参照组）相比，被分类为活跃/低久坐组在坐位体前屈方面处于HFZ的可能性增加（优势比，2.55；95%置信区间，1.96 - 3.32），并且具有更高的体能综合得分（优势比，1.38；95%置信区间，1.13 - 1.69）。
独立于久坐时间，MVPA时间与更好的体能相关。被分类为活跃/低久坐的参与者处于HFZ的几率更高，柔韧性更好，并且体能综合得分更高。这些发现表明，MVPA时间有助于青少年获得更好的体能。
