Prior maximal exercise decreases pulmonary diffusing capacity during subsequent exercise.
Pulmonary diffusion (DLCO) increases during exercise due to greater pulmonary capillary volume (Vc) and membrane diffusing capacity (DM). However, after heavy exercise there is a reduction in resting DLCO. It is unclear whether this post-exercise effect will attenuate the normal increase in DLCO, Vc and DM during subsequent exercise and whether this affects SpO2 (pulse oximeter). DLCO, Vc, DM, cardiac output and SpO2 were measured at rest, moderate (~70% VO2peak) and heavy (~90 VO2peak) exercise in 9 subjects during 2 sessions separated by ~90 min. DLCO, Vc and DM increased during exercise (P<0.05). DLCO (P<0.05) and Vc (P<0.10), but not DM or SpO2 were lower in session 2 compared to the first. Reductions in DLCO and Vc appeared to be smallest during rest (1-4%) and greatest at high-intensity exercise (8-20%), but the interaction was not significant. SpO2 decreased by 4.9% and 5.1% from rest to high-intensity exercise during the first and second exercise bout, but these changes were not different. These data confirm that a bout of high-intensity exercise reduces DLCO and Vc, and may indicate that these changes are exacerbated during subsequent high-intensity exercise. Despite these changes, SpO2 was not affected by previous exercise.
Medicine, University of Otago, Dunedin, New Zealand.
J C
JC
Baldi
Biological Sciences, Northern Arizona University, Flagstaff, United States.
M J
MJ
Dacey
Biological Sciences, Northern Arizona University, Flagstaff, United States.
M J
MJ
Lee
Biological Sciences, Northern Arizona University, Flagstaff, United States.
J R
JR
Coast
D000293:Adolescent; D000328:Adult; D001810:Blood Volume; D002196:Capillaries / Q000502:physiology; D002302:Cardiac Output; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008168:Lung / Q000098:blood supply; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D005082:Physical Exertion / Q000502:physiology; D011650:Pulmonary Alveoli / Q000502:physiology; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D055815:Young Adult
D010100:Oxygen