Physical Activity Patterns From Late Childhood To Young Adulthood

Abstract

Physical activity is a critical component of a healthy lifestyle and in childhood has been shown to be related to biological age. Since physical activity is declining in childhood the concern is that these low physical activity levels will track into adulthood. PURPOSE To investigate trends and tracking of physical activity from late childhood into young adulthood. METHODS Subjects were part of the Saskatchewan Pediatric Bone Mineral Accrual Study (PBMAS) (1991–1997), aged 8 to 15 years at study entry. 153 individuals were reassessed between 2002 and 2004 (aged 21 to 28 years). Height and physical activity were measured bi-annually. During childhood an age at peak height velocity (PHV) was determined. Subjects were aligned by biological age (years from PHV) to control for maturity differences. Physical activity was assessed using throughout the study using the Physical Activity Questionnaire for children (PAQ-C), adolescents (PAQ-A) and adults (PAQ-AD). Data were analyzed using Pearson correlations and independent t-tests. RESULTS At study entry subjects were aged between −4 and +2 years PHV. Physical activity reached a peak −1 years from PHV and significantly decreased until +6 years PHV (p <0.05). No significant (p>0.05) changes were seen in PA scores between +6 and +14 years PHV. When categorized in three year intervals from −3 years PHV to +4 years PHV, PA scores significantly correlated (p <0.05), e.g. −4 to −1 years PHV r=0.23 to +4 to+7 years PHV r=0.69. Correlation coefficients decreased with increasing time intervals. When categorized by 9 year intervals the correlations for −3 to +6 years PHV were r=0.17 compared to r=0.26 from +3 to +12 years PHV. CONCLUSIONS Physical activity decreased during adolescence but plateaued on entry into adulthood. Tracking of physical activity from childhood to adulthood was low to moderate, indicating there was potential for change in activity levels overtime.