Objective: To explore the relationship between adolescents’ physical activity and motor skills, and to provide a new perspective for the promotion of adolescents physical activity. Methods: The subjects were 153 adolescents aged 12-14, including 73 boys and 80 girls were selected as participants. The accelerometer (ActiGraph GT3X+) was used to measuring physical activity of the subjects for 7 consecutive days. The Movement Assessment Battery for Children, Second Edition (MABC-2) was used to measure the level of development of motor skills. Results: The average time for subjects to participate in moderatetovigorous physical activity(MVPA) was 42.15 minutes per day, 15.7% of the subjects met the World Health Organization physical activity guidelines. 56% of subjects had an average level of motor development. There was a positive correlation between MVPA and the object control skill score(r=0.20, P<0.05). There was a positive correlation between low intensity physical activity and fine motor scores(r=0.23, P<0.01); There was a low correlation between moderatehigh intensity physical activity and object control in boys(r=0.29, P<0.05), and no correlation was found among girls. Conclusion Time spent in moderatetovigorous physical activity among adolescents is still insufficient. The mutual promotion of physical activity and motor skill provides a new perspective for developing the motor skills of children and adolescents to improve moderatetovigorous physical activity.

Objective: The purpose of this study is to explore the interactive correlations and the influence of physical activity and motor skills on physical condition of adolescents, in order to provide a theoretical basis for adolescent s physical fitness promotion. Methods: Random cluster sampling method was used to select 164 adolescents aged 12-14. The development of motor skills was measured by MABC 2(Movement Assessment Battery for Children 2), and physical activity was measured by ActiGraph GT3X+ type accelerometer. Physical fitness test selected "Chinese National Students Physical Fitness Standard(CNSPFS)" (for middle school students) in the 1 000/800 meters run, standing long jump and sitting forward flexion. Pearson correlation was used to analyze the correlations among physical activity, motor skills and physical fitness, and multiple stepwise regression was used to analyze the influence of physical activity and motor skills on physical fitness. Results: There was a low degree of positive correlation between physical activity and physical condition( r=0.24-0.30, P <0.05); There was a low to moderate positive correlation between motor skills and physical condition( r=0.21-0.42, P <0.05). Physical activity and BMI could explain for 31% of cardiorespiratory endurance. Physical activity, object control and BMI could explain for 26% of muscle strength, balance skills could explain for 5% of flexibility. Conclusion There is a low to moderate correlation between physical activity, motor skills and physical fitness. Physical activity and motors skills are associated with adolescent s physical fitness level. Comprehensive interventions that promote the development of motor skills and participation in physical activity have practical significance for improving adolescents physical fitness.