Deng Pengyu, Ozaki Hayao, Natsume Toshiharu, Ke Dandan, Lu Dajiang, Suzuki Koya, Naito Hisashi
Graduate School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan.
Institute of Health and Sports Science & Medicine, Juntendo University, Chiba 270-1695, Japan.
Children (Basel). 2023 Sep 11;10(9):1538. doi: 10.3390/children10091538.
Physical activity (PA) is likely to be the most important modifiable factor in skeletal muscle development. However, the influence of PA on the skeletal muscle of preschool children has not been thoroughly investigated. The main objective of this study was to quantitatively measure PA, and then, to assess whether associations exist between site-specific muscle changes and PA in relation to sex and weight statuses in preschool children aged 3 to 4 years.
A total of 86 healthy preschool children, aged 3-4 years, were instructed to wear an accelerometer for seven consecutive days. The number of steps taken daily, and minutes spent in moderate-vigorous PA (MVPA) and total PA (TPA) were recorded. Muscle thickness was measured by B-mode ultrasonography using a 5-18 MHz scanning head. Muscle thickness was measured at seven sites: the lateral forearm, upper arm, abdomen, anterior and posterior thigh, and anterior and posterior lower leg.
There was no significant difference between boys and girls in terms of MVPA and TPA on weekdays and weekends. According to the linear regression models, after adjusting for daylight duration, the muscle of the posterior thigh was significantly positively associated ( < 0.05) with daily steps and MVPA on weekdays for boys and girls, respectively.
We found that the muscle thickness of the posterior thigh in preschool children was significantly positively associated with PA, as measured by daily steps and MVPA. We suggest that for the overall health and well-being of preschool children, the levels of PA should be maintained and/or increased, and preferably transformed into a regular part of daily living.
身体活动（PA）可能是骨骼肌发育中最重要的可改变因素。然而，PA对学龄前儿童骨骼肌的影响尚未得到充分研究。本研究的主要目的是定量测量PA，然后评估3至4岁学龄前儿童特定部位肌肉变化与PA之间是否存在与性别和体重状况相关的关联。
共有86名3 - 4岁的健康学龄前儿童被要求连续七天佩戴加速度计。记录每日步数、中度至剧烈身体活动（MVPA）和总身体活动（TPA）所花费的分钟数。使用5 - 18 MHz扫描头通过B型超声测量肌肉厚度。在七个部位测量肌肉厚度：前臂外侧、上臂、腹部、大腿前后侧以及小腿前后侧。
在工作日和周末，男孩和女孩在MVPA和TPA方面没有显著差异。根据线性回归模型，在调整日照时长后，男孩和女孩大腿后侧的肌肉分别与工作日的每日步数和MVPA显著正相关（<0.05）。
我们发现，通过每日步数和MVPA测量，学龄前儿童大腿后侧的肌肉厚度与PA显著正相关。我们建议，为了学龄前儿童的整体健康和幸福，应维持和/或增加PA水平，最好将其转变为日常生活的常规部分。
