Julian David Pillay, Tracy Lynn Kolbe-Alexander, Willem van Mechelen and Estelle Victoria Lambert
Pedometer-based recommendations for accumulating steps/d largely focus on volume, with less emphasis on intensity and fitness/health outcomes. We aim to examine this relationship.
A convenience sample (N = 70, 35 men, 32 ± 8yrs) wore a pedometer (4 days). The pedometer classified steps as “aerobic” (≥ 60 steps/minute, minimum duration of 1 minute) or “non-aerobic” (< 60 steps/minute and/or < 1 minute). Estimated maximal oxygen uptake (VO2max), derived from a 12-minute submaximal step-test, and health outcomes: blood pressure (BP), body mass index (BMI), percentage body fat (%BF), and waist circumference (WC) were correlated with pedometer data. Participants were grouped according to number and intensity of steps: LOW (< 5000 steps/d), HIGH-LOW (≥ 5000 steps/d, no aerobic steps), HIGH-HIGH (≥ 5000 steps/d, including some aerobic steps). Analyses of covariance, adjusting for age, gender, and total steps/d were used to compare groups.
Average steps/d was 6520 ± 2306. Total steps/d and total time spent accumulating “aerobic” steps (minutes/day) were inversely associated with %BF, BMI, WC, and systolic BP (P < .05). After adjusting for gender and total steps/d, %BF was different between all 3 groups, VO2max was different between the LOW and HIGH-HIGH groups, WC was lower in the HIGH-HIGH versus the other 2 groups (P < .03, respectively).
Intensity seems an important factor to consider in steps/d cut-points.
Monika Uys, Catherine Elizabeth Draper, Sharief Hendricks, Anniza de Villiers, Jean Fourie, Nelia Steyn and Estelle Victoria Lambert
The purpose of this study was to assess factors that influence physical activity (PA) levels during break-times in South African primary school children.
The System for Observing Play and Leisure Activities in Youth (SOPLAY) was used to observe PA levels during break-times at low-income schools (4 intervention, 4 control). The intervention was based on action-planning including: school environment, curriculum, and family involvement. Categories of observed activity included Sedentary, Eating, Walking, or Vigorous PA. Contextual factors assessed included teacher supervision, equipment, and crowding. Chi-square tests were used to determine associations between PA levels and contextual factors.
In the 970 observations made, 31% of learners were sedentary, 14% were eating, 29% were walking, and 26% were engaged in vigorous PA. There were no differences in break-time PA between intervention and control groups (NS). With supervision, children were more likely to eat and less likely to do vigorous PA (P = .035). Playground crowding was associated with lower levels of vigorous activity and more sedentary behavior (P = .000).
PA during break-time was adversely affected by over-crowding and lower with supervision. The results suggest that interventions may be targeted at the school policy environment to reduce these barriers to PA.