Heart rate response to bicycle ergometer exercise in children ages 6-7 years

The purpose of the present investigation was to compare the heart rate response of pre-pubertal males and females during rest, steady-rate power output, peak power output, and recovery. Sixty-six children (38 males and 28 females) ages 6-7 years performed a continuous bicycle ergometer exercise test, including 4 min of steady-rate work (males = 15.3 +/- 0.17 W.min-1, females = 15.0 +/- 0.16 W.min-1) followed by a progressive increase in resistance until volitional fatigue, and a 5-min recovery period immediately following termination of exercise. Mean steady-rate heart rate response of 119.0 +/- 1.75 beats.min-1 for males was significantly (P less than 0.05) lower than the females (132.1 +/- 2.92 beats.min-1). Peak heart rate response was similar between the sexes (190.1 +/- 1.21 and 192.1 +/- 1.73 beats.min-1 for males and females, respectively; P greater than 0.05). Sex differences in heart rate recovery from peak values were significant (P less than 0.05) during the first 3 min of the 5-min recovery period, but not thereafter (P greater than 0.05). It was concluded that sex differences in heart rate response were present in these prepubertal children at rest, during steady-rate power output, and during the first 3 min of recovery.