北京市某初中1～2年级学生在校身体活动水平定量评估

Objective assessment of school-time physical activity of a grade 1-2 junior school students in Beijing

目的定量测量北京市初中1～2年级学生在校期间(尤其是体育课上)的身体活动水平。方法选取北京市某初中1～2年级学生81名(男生37人,女生44人),用佩戴于髋关节的ActiGraph GT3X+型加速度计记录一周5d在校期间身体活动,评价平均每天和每节体育课上的身体活动水平。结果在校期间,平均每天参加中高强度活动时间女生为(47.2±16.0)min,男生为(67.3±20.5)min,女生显著低于男生(P<0.01);体育课上达到中高强度活动的时间比例男生平均为53.6%±10.2%,女生为35.2%±7.2%;不同BMI学生在校期间身体活动水平比较:平均每天身体活动水平男女各组间均无差异;体育课上,女生各组间无差异;与正常BMI组男生相比,消瘦、超重和肥胖组男生较高强度活动时间较短(P<0.05)。结论初中1～2年级女生身体活动强度较低;体育课对促进学生在校期间的身体活动有重要贡献,体育课日学生身体活动明显增加;体育课上,正常体重男生身体活动量最高。

Objective To quantify the physical activity（PA） level during school time,especially in PE class,among Beijing junior school students.Methods 81 healthy adolescents（37 boys and 44 girls） aged 11-15 were recruited from grade 1-2 of a junior school,and a hip-worn ActiGraph GT3X＋ accelerometer was used to measure students＇ PA.Accelerometer-determined steps,moderate-and vigorous-intensity PA（MVPA）,vigorous-intensity PA（VPA） and MET-mins at school time and physical education（PE） class were assessed.Results During school time,girls spent（47.2±16.0）mins performing,and boys（67.3±20.5）mins per day（P〈0.01）.Boys also had more steps per day,VPA time and MVPA MET-min than girls（P0.001）.In PE class,boys spent 53.6%±10.2% of time in MVPA,as compared to girls＇ 35.2%±7.2%.Boys with normal BMI had the highest VPA time during PE than other groups（P〈0.05）.No significant BMI group differences in PA level were found in girls.Conclusion PA in school time was objectively qualified in Beijing junior school students.Girls were less active than boys.PE class provided a major portion of the VPA time and MVPA MET-min in school time PA for boys and girls.Boys with normal BMI had the highest PA level during PE classes.