Current status of physical activities among preschool children and relationship of activity type with bone mass / 中华健康管理学杂志

ABSTRACT

Objective To investigate physical activities of preschool children by gender and to explore the effects of activity type on bone indexes.Methods During 2009 and 2010,397 preschool children of 3-5 years old were randomly selected from 4 kindergartens in Chengdu Province of China.Ultrasound bone analyzer was used to assess children's bone mass.A physical activity questionnaire was completed by parents to evaluate physical activities at leisure time.Student's t test and least square regression were used for data analysis.Results Concerning activity types,boys spent more leisure time on running and Wushu than girls did (t values were 1.94 and 2.84,respectively ; both P ＜ 0.05).However,girls spent more time on dancing (0.78 h),jumping rope (0.08 h) and manual labour (0.22 h) each day (t values were-9.50,-3.43 and-1.92,respectively; all P ＜ 0.05).The weekly total exercise time and energy consumption per unit of body weight of girls vs.boys were 7.29 vs.6.51 h and 127.57 vs.113.85 kJ (t values were 2.63 and 2.04,respectively ; both P ＜ 0.05).About per day time on sleeping and per week time on watching television,there were no significant difference between boys and girls (t =0.180,0.520;P ＞0.05).But boys spent more time on electronic game and computer than girls (t =0.760,2.510;P ＜ 0.05).The normalized correlation coefficient for bone mass and moderate physical activities or jumping was 0.184 and 0.275,respectively (both P ＜ 0.05).Conclusions Our data suggest that preschool children's bone volume may be positively correlated with moderate physical activities and jumping activities.Introducing some moderate physical activities or activity appliance,toys and playing fields as well as increasing professional training might be helpful.