This study examined the relationship between airway blood flow (over(Q, ̇)aw), ventilation (over(V, ̇)E) and cardiac output (over(Q, ̇)tot) during exercise in healthy humans (n = 12, mean age 34 ± 11 yr). over(Q, ̇)aw was estimated from the uptake of the soluble gas dimethyl ether while over(V, ̇)E and over(Q, ̇)tot were measured using open circuit spirometry. Measurements were made prior to and during exercise at 34 ± 5 W (Load 1) and 68 ± 10 W (Load 2) and following the cessation of exercise (recovery). over(Q, ̇)aw increased in a stepwise fashion (P < 0.05) from rest (52.8 ± 19.5 μl min-1 ml-1) to exercise at Load 1 (67.0 ± 20.3 μl min-1 ml-1) and Load 2 (84.0 ± 22.9 μl min-1 ml-1) before returning to pre-exercise levels in recovery (51.7 ± 13.2 μl min-1 ml-1). over(Q, ̇)aw was positively correlated with both over(Q, ̇)tot (r = 0.58, P < 0.01) and over(V, ̇)E (r = 0.50, P < 0.01). These results demonstrate that the increase in over(Q, ̇)aw is linked to an exercise related increase in both over(Q, ̇)tot and over(V, ̇)E and may be necessary to prevent excessive airway cooling and drying.
- Bronchial blood flow
- Cardiac output
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine