Senitko, Annette N.

In sedentary individuals, postexercise hypotension after a single bout of aerobic exercise is due to a peripheral vasodilation. Endurance exercise training has the potential to modify this response and perhaps reduce the degree of postexercise hypotension. We tested the hypothesis that endurance exercise-trained men and women would have blunted postexercise hypotension compared with sedentary subjects but that the mechanism of hypotension would be similar (i.e., vasodilation). We studied 16 endurance-trained and 16 sedentary men and women. Arterial pressure, cardiac output, and total peripheral resistance were determined before and after a single 60-min bout of exercise at 60% peak oxygen consumption. All groups exhibited a similar degree of postexercise hypotension (∼4–5 mmHg; P < 0.05 vs. preexercise). In sedentary men and women, hypotension was the result of vasodilation (Δresistance: −8.9 ± 2.2%). In endurance-trained women, hypotension was also the result of vasodilation (−8.1 ± 4.1%). However, in endurance-trained men, hypotension was the result of a reduced cardiac output (−5.2 ± 2.4%; P < 0.05 vs. all others) and vasodilation was absent (−0.7 ± 3.3%; P < 0.05 vs. all others). Thus we conclude the magnitude of postexercise hypotension is similar in sedentary and endurance-trained men and women but that endurance-trained men and women achieve this fall in pressure via different mechanisms.