Heart Rate and Perceived Exertion in Healthy Weight and Obese Children During a Self-Selected Physical Activity Program.

Background: Compared with structured/organized activities, unstructured, self-selected physical activity (PA) may be more appealing for children in particular obese (OB) children. We examined whether both healthy-weight (HW) and OB children would engage in moderate to vigorous intensity PA during an unstructured PA program and compared heart rate (HR) and rate of perceived exertion (RPE) between the children. Methods: Twenty-one children [9 OB (≥95th BMI percentile, 12 HW (5th – <85th), 8.6 ± 0.8 years; 9 males, 12 females] participated in before-school (7:30 AM to 8:15 AM) PA for 18 weeks, 3 consecutive days/week. Each child wore a Polar E600 HR monitor and was provided a vigorous, age-targeted heart rate (THR) of 70%. Results: Mean HR ≥ vigorous THR for all children in 65.3% of the sessions and exceeded moderate intensity in 100%. Over the 18-weeks, no significant difference was observed in the overall mean HR between the HW (171.4 ± 12.0) and OB (169.3 ± 13.0), however the OB reported significantly low...