HEART RATES BECOME LOWER WITH AGE AND ATTENTION DEMANDS BUT THEIR VARIABILITY REMAINS CONSISTENT
Wood, R., Lee, M., Bao, D., Hemard, L, & Maraj, B. (1998). Short-term heart rate variability during a cognitive challenge in young and old subjects. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 1422.
Attention demanding tasks may cause changes in the autonomic modulation of cardiac function. Heart rate variability, an index of autonomic modulation of heart rate, is thought to decrease with age. This study investigated heart rate variability in young and old Ss at rest and during an attention-demanding task. Older Ss (N = 16) ranged in ages from 72-91 years and the younger Ss (N = 16) were college students ranging in ages from 20-25 years.
At rest, the older group's heart rate (29.3 bpm) was significantly lower than the younger group (HR = 60.7 bpm). In the attention test condition the older group dropped to 22.9 bpm while the younger group dropped to 50.6 bpm but the variability of responses was not significantly different between the groups.
Implication. Resting heart rate and heart rates during an attentional task are lower for older individuals than younger individuals. However, the variability of heart rates is similar for both groups. If heart rates are to be used as indexes of exercise, they need to be adjusted for the age-group and the degree of attention demanded by the task.
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