Kinesiology Department, Texas Christian University, Fort Worth, TX 76129, USA.
Int J Environ Res Public Health. 2024 Sep 30;21(10):1304. doi: 10.3390/ijerph21101304.
Obesity and inactivity among children are at an all-time high and have been steadily increasing in prevalence over the last thirty years. The school environment provides the ideal setting for reaching a large number of children across diverse populations in order to reverse these trends. However, there are many inconsistent results yielded by school-based physical activity interventions due to implementation length, time for activities, and the use of structured physical activities. The LiiNK Project is a whole-child intervention addressing these gaps by providing children 45-60 min of recess (unstructured, outdoor play) in their schools daily, while the control children are allowed to engage in recess for 30 min daily. The purpose of this study was to compare the physical activity intensity and obesity rates of third- and fourth-grade children participating in the LiiNK intervention, which provides 60 min of recess for third graders and 45 min for fourth graders, to those in a control group allowed 30 min of daily recess.
The children were 8-10 years old (M = 9.2; 52% females and 48% males). The intervention children comprised 90 third graders and 100 fourth graders, and the control children comprised 101 third graders and 92 fourth graders. Physical activity levels were monitored using accelerometers to assess sedentary, light, and moderate-to-vigorous physical activity (MVPA). Obesity rates were evaluated using bio-electrical impedance analysis (BIA), in which body fat percentage is calculated based on normative values using age and sex in the equation.
The third-grade intervention children engaged in 13 more MVPA minutes and took 900 more steps daily than their control counterparts, and also presented a greater proportion of overweight children transitioning to a healthy weight status from the fall to the spring semester. Conversely, the fourth-grade control children increased their activity by 500 steps and 15 more MVPA minutes daily. Despite this, the intervention children overall demonstrated a reduction in body fat percentage, while the control children demonstrated an increase in body fat percentage.
Ultimately, 60 min of unstructured, outdoor play in schools provides children the best opportunity to engage in MVPA, which may positively impact body fat percentages, offering a potential strategy for combatting childhood obesity in school settings.
儿童肥胖和缺乏运动的问题达到了前所未有的高度，且在过去三十年中患病率一直在稳步上升。学校环境为接触不同人群中的大量儿童提供了理想的场所，以便扭转这些趋势。然而，由于实施时间、活动时间和使用结构化体育活动的不同，基于学校的体育活动干预措施的结果存在很大差异。LiiNK 项目是一项针对全儿童的干预措施，通过每天在学校为儿童提供 45-60 分钟的课间休息（非结构化、户外游戏）来解决这些差距，而对照组的儿童则每天允许进行 30 分钟的课间休息。本研究的目的是比较参加 LiiNK 干预的三、四年级儿童的身体活动强度和肥胖率，该干预措施为三年级儿童提供 60 分钟课间休息，为四年级儿童提供 45 分钟课间休息，与允许每天进行 30 分钟课间休息的对照组进行比较。
儿童年龄为 8-10 岁（M = 9.2；52%为女性，48%为男性）。干预组儿童包括 90 名三年级学生和 100 名四年级学生，对照组儿童包括 101 名三年级学生和 92 名四年级学生。使用加速度计监测身体活动水平，以评估久坐、轻度和中等到剧烈身体活动（MVPA）。使用生物电阻抗分析（BIA）评估肥胖率，根据年龄和性别在方程中计算体脂百分比。
三年级干预组儿童每天多进行 13 分钟 MVPA，多走 900 步，与对照组相比，超重儿童从秋季到春季学期向健康体重状态转变的比例更高。相反，四年级对照组儿童每天增加了 500 步和 15 分钟 MVPA。尽管如此，干预组儿童总体上表现出体脂百分比的降低，而对照组儿童则表现出体脂百分比的增加。
最终，学校中非结构化、户外的 60 分钟游戏为儿童提供了参与 MVPA 的最佳机会，这可能对体脂百分比产生积极影响，为在学校环境中对抗儿童肥胖提供了一种潜在策略。
