Thirteen children each exercised for 6 min by running on a treadmill and by tethered swimming, breathing air at room temperature and either 8% or 99% relative humidity continuously. Ventilation, gas exchange and heart rate were closely matched in all four tests in each child, with a mean oxygen consumption of 32.3±1.7ml·min-1·kg-1. The post-exercise fall in FEV1 expressed as a percentage of the baseline FEV1 (δFEV1) was significantly greater after running compared with swimming breathing either humid or dry air. The δFEV1 was also related to respiratory heat loss (RHL) calculated from measurements of inspired and expired gas temperature and humidity. At a standardised RHL, the difference between running and swimming was highly significant [δFEV1 (%) ± SE=39±5 and 28±4 respectively, p<0.01]. These experiments suggest that the type of exercise influences the severity of exercise-induced asthma even under conditions of the same metabolic stress and respiratory heat loss.
|Number of pages||11|
|Journal||European Journal of Applied Physiology and Occupational Physiology|
|State||Published - 1 Apr 1982|
- Exercise-induced asthma
- Respiratory heat loss
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health