Background: Recess and physical education time continue to diminish, creating a need for additional physical activity opportunities within the school environment. The use of school gardens as a teaching tool in elementary science and math classes has the potential to increase the proportion of time spent active throughout the school day. Methods: Teachers from 4 elementary schools agreed to teach 1 math or science lesson per week in the school garden. Student physical activity time was measured with ActiGraph GT3X accelerometers on 3 garden days and 3 no-garden days at each school. Direct observation was used to quantify the specific garden-related tasks during class. The proportion of time spent active and sedentary was compared on garden and no-garden days. Results: Seventy-four children wore accelerometers, and 75 were observed (86% participation). Children spent a significantly larger proportion of time active on garden days than no-garden days at 3 of the 4 schools. The proportion of time spent sedentary and active differed significantly across the 4 schools. Conclusions: Teaching lessons in the school garden may increase children’s physical activity and decrease sedentary time throughout the school day and may be a strategy to promote both health and learning.
Erika Rees-Punia, Alicia Holloway, David Knauft and Michael D. Schmidt
Erika Rees-Punia, Charles E. Matthews, Ellen M. Evans, Sarah K. Keadle, Rebecca L. Anderson, Jennifer L. Gay, Michael D. Schmidt, Susan M. Gapstur and Alpa V. Patel
This study examined the test-retest reliability and criterion validity of light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous (MVPA) physical activity survey items in a subset of participants from a large prospective cohort. Participants included 423 women and 290 men aged 31–72 years in the Cancer Prevention Study-3 (CPS-3). Information on physical activity (PA) was collected using two different surveys: one survey which captures all activity performed during a typical 24-hour period in broad categories (24-hour survey), and a more detailed survey focused primarily on leisure-time PA (LTPA survey). One-year reliability was assessed by computing Spearman correlation coefficients between responses from pre- and post-study periods for both surveys. Validity was assessed by comparing survey-estimated PA with accelerometry, seven-day diaries, and a latent variable representing ‘true’ PA estimated through the method of triads. Reliability was considered acceptable for most items on the LTPA survey (range ρ = 0.45–0.92) and the 24-hour survey (range ρ = 0.37–0.61). LPA validity coefficients were higher for the 24-hour survey, while MPA, VPA, and MVPA coefficients were higher for the LTPA survey. Study results suggest that both CPS-3 PA surveys are suitable for ranking or classifying participants in our population according to overall PA category or intensity-specific activity level.