Past Year Sport Participation, Not Current Physical Activity, Is Associated With Fitness Level In Urban Adolescent Girls

Abstract

Purpose It has been shown that physical activity levels decline during adolescence for black and white girls. Baseline data from a trial designed to increase physical activity in high school girls were used to describe previous sport participation and current physical activity behavior and fitness level. Methods Measures included a 3-stage aerobic step test, a 7-day physical activity recall to estimate daily energy expenditure, heart rate and accelerometer monitoring, and sport participation questions from the Youth Risk Behavior Surveillance Survey. At the time of data collection, the sport participation measure determined participation in the 8th grade school year, and the 7-day recall measured current physical activity level in the 9th grade. Results Participants' fitness level was classified into 4 stages. Fourteen percent of participants completed stage 1 (unfit), 28% completed stage 2 (low fit), 27% completed stage 3 reaching target heart rate (THR) (fit), and 31% completed stage 3 without reaching THR (high fit). Over half the sample (52.5%) reported no organized sport participation in the past 12 months; 17.6% had participated in at least one community sport, 12.2% had participated in at least one school sport, and 17.6% had participated in a community sport and in a school sport. School sport participation was related to fitness category in the expected direction χ2=10.65, p=0.014). One-way ANOVA tests showed no significant difference in daily energy expenditure across fitness categories. Time spent in physical activity was broken down into 5 weekday time periods and 3 weekend time periods; of these 8 time periods, the only difference in activity level was between the low-fit and high-fit groups on weekday evenings (±SD=0.34 ± 0.59, 1.04 ± 1.7 hours per week, respectively, p=0.02). However, according to the heart rate monitoring data, the low-fit group spent significantly more time (mean ± SE=2.9 ± 0.38%) with heart rates above 124 beats per minute than the fit and high-fit groups (1.7 ± 0.37%, 1.6 ± 0.38% respectively, p<0.03). Conclusions It is possible that these cross-sectional data show some fitness carryover from past year sport participation and physical activity level, while the current physical activity level was very low. Further, it is hypothesized that the low-fit group was sufficiently low in cardiorespiratory fitness to elicit “exercise” heart rates while performing activities of daily living usually considered light activity. Based on the current activity level, a decline in fitness level over time is expected in this population. Supported by National Heart, Lung, and Blood Institute Grant R01 HL63861