Age and thermoregulatory blood flow during treadmill exercise

Abstract

The purpose of this study was to determine if age impacts the cutaneous vascular (thermoregulatory) response to exercise in women. Seven healthy women ages 20–24 were studied and compared to a group of seven healthy women ages 51–58. The exercise consisted of 20 min of brisk treadmill walking at a room temperature of 32 deg Celsius and a relative humidity of 45%. Skin blood flow (SBF) at the anterior forearm (dominant arm) and mid‐back was recorded immediately before and then throughout the exercise. A dual‐channel laser Doppler flowmeter was used to measure the SBFs, and the values were stored in computer and later analyzed by commercial software. Using ANOVA procedures mean SBFs for both skin locations were then compared before and at 2 min intervals during the exercise. The responses in the two age groups were then compared to determine if age had an effect on the vascular responses to exercise. Results showed vasodilation at each skin location in both groups with exercise. When the two groups were compared, it was found that the vascular responses were most pronounced in the younger group. The forearm SBF was 23% higher in the young group (P<0.05), and it was 34% higher at the back (P<0.05). The differential vascular responses to exercise between the two groups are likely explained by the effects of age on the structure and function of the cutaneous microcirculatory bed.