Evaluación por acelerometría del ejercicio realizado por escolares chilenos durante una clase de educación física y su relación con el estado ponderal

Background: The physical education subject (PES) should be capable of activating the exercise recommendations required to promote healthy lifestyle in children. Objective: To compare metabolic activity, energy expenditure, amount of exercise, and intensity of physical effort in children during a PES class, and to relate them to their body mass index. Participants and Methods: A total of 120 schoolchildren (63 boys aged 8.0 ± 1.4 years old; 57 girls aged 8.3 ± 1.6 years old) were grouped in normal weight (NW), overweight (OW), and obese (OB) categories based on their body mass index, and their body movements were measured with accelerometer during a PES class. Results: Energy expenditure related to body weight induced by exercise was higher in the NW group (4.7 ± 1.8 kcal/kg) than in the OW (3.4 ± 1.7 kcal/kg) and OB (2.8 ± 1.3 kcal/kg) groups, with P<0.05. Additionally, the NW group remained at very vigorous effort levels longer during the PES class (2.3 ± 2.2 min), as well as they spent less time on light exercise (9.5 ± 2.6 min) than the OB group (1.8 ± 2.5 min and 11.1 ± 2.3 min, respectively), with P<0.05. There were no differences in the number of movements (total steps) and metabolic activity (MET) between groups (P>0.05). Conclusions: NW schoolchildren are able to spend more energy in relation to their body weight and with a greater intensity of exercise than their OB peers during a PES class.