Calf blood flow and vascular resistance during reactive hyperaemia in young athletes and trained middle-aged subjects.

The effect of training on dilatation capacity in the lower limbs was evaluated by studying the blood flow and vascular resistance in the calf in 10 young athletes aged 19-29 years and 15 trained middle-aged subjects aged 52-58 years during post-ischaemic reactive hyperaemia. The control groups comprised untrained subjects of approximately the same ages, i.e. 16 men aged 18-29 and 37 aged 40-60. The calf blood flow as determined plethysmographically and the blood pressure was measured on the arm by auscultation. Vascular resistance was calculated from the mean blood pressure and from the maximal calf blood flow measured during hyperaemia. A significantly higher maximal blood flow and significantly lower resistance in the calf were found in young athletes than in untrained subjects. In athletes, the flow debt was significantly overpaid. In middle-aged subjects, the effect of training was manifested only in significant overpayment of the flow debt, while vascular resistance and the maximal blood flow were the same as in the controls. It can be concluded from these findings that significant improvement of vasodilatation ability in association with training occurs primarily in young subjects. The findings also correspond to the known ability of young athletes to give a higher maximal performance than veteran athletes.