Daily Physical Activity Patterns of Prepubertal Children Involved in a Vigorous Exercise Program

Abstract

The purpose of the present investigation was to examine the effects of a vigorous physical activity program on daily physical activity patterns of 59 7-year-old children divided into experimental (n = 26) and control (n = 33) groups. The experimental group participated in a 25-min vigorous, aerobic exercise session 4 days per week, while the control group maintained their normal daily activities, which included a 1 day per week physical education class, for 8 months. The intensity of each experimental exercise session and each control physical education class was determined by fitting Exersentry heart rate devices to two different children randomly selected from each group without replacement. Daily activity patterns were determined using minute-by-minute heart rates calculated from a 12-h EKG recorded from 8 a.m. to 8 p.m. using an Oxford Instruments ambulatory monitor. Analysis of the Exersentry data demonstrated significantly higher heart rates (P less than 0.05) during the experimental exercise session compared to the control physical education class, except during pre-exercise. Analysis of the 12-h EKG data (n = 720 min) revealed the experimental group spent significantly more time (P less than 0.05) at heart rates greater than 160 bts X min-1 (35 +/- 6 min, experimental; 21 +/- 3 min, control) during the intervention program. No significant group differences (P greater than 0.05) were observed in 12-h heart rate data collected prior to initiation of the intervention program. These data suggest that a vigorous physical activity program resulted in differences in the daily physical activity patterns of 7-year-old children.