PULMONARY FUNCTIONS OF HEALTHY ELITE RUNNERS IN WINTER AND POLLEN-SEASON OUT DOOR RUNNING TEST 533

Abstract

Exercise induced bronchoconstriction (EIB) causes reduction of peak expiratory flow (PEF) or in forced expiratory flow in one second (FEV1) after exercise when compared with pre-exercise values. Cold air and pollen season are known to exacerbate bronchoconstriction in asthmatic persons. Therefore we studied variations of PEF and FEV1 in 11 healthy runners (7 men, 4 women), mean age 21.1 yrs both in winter (subzero conditions) and in spring (after highest birch pollen season). Their resting spirometric values were normal, skin prick tests with ten air-borne allergens negative, histamine challenge test showed no bronchial hyperrectivity, questionnaire and personal interview did not indicate symptoms of EIB. The runners performed exercise challenge test (2000m running on a cross-country track) at 85% of their maximal heart rate. FEV1 and PEF were measured before and at 4′, 10′ and 20′ after the run. In winter mean maximal change in FEV1 was +1.9% (SD 3.0%) and in PEF-5.5% (SD 3.4%). In summer the values were +2.4% (SD 3.3%) and -5.1% (SD 5.9%), respectively. The largest single decrease in FEV1 was -3% and in PEF-15%. Changes in FEV1 were small and individual variation was greater in PEF than in FEV1 in these healthy runners. Thus, measurement of FEV1 is preferable to PEF. A decrease in post-exercise FEV1 values more than 6% (= mean -2× SD) and a decrease in post-exercise PEF values more than 17% can be considered as abnormal. Our results can be used in the evaluation of EIB in elite runners when using free running exercise challenge test.