Exercise-induced changes in postexercise pulmonary function have not been studied in healthy elite athletes in normal training conditions. Twelve healthy elite runners volunteered. They showed normal resting spirometry and bronchial responsiveness to histamine, and were non-atopic. They performed free running exercise challenge tests (ECT) at subzero temperature and immediately after highest birch pollen season. The mean maximal postexercise changes in FEV(1), PEF, FVC, and FEV(1)/FVC did not differ between the cold air and pollen season ECTs. Compared with pre-exercise values, FEV(1)increased significantly at 10 min (p = 0.028) and 20 min (p = 0.033) postexercise in the cold air ECT, as well as at 10 min (p = 0.024) and 20 min (p = 0.010) postexercise in the pollen season ECT. The mean (SEM) maximal postexercise change in FEV(1) was mostly small + 2.6 (0.6)% in the winter and + 2.7 (0.9)% in the pollen season. In contrast, significant decreases in PEF, compared with baseline, were found at 10 min (p = 0.071) and 20 min (p = 0.0029) postexercise in the cold air ECT, as well as at 10 min (p = 0.060) and 20 min (p = 0.010) postexercise in the pollen season ECT (p = 0.0076). The mean (SEM) maximal postexercise fall in PEF was 5.9 (1.0)% in the winter and 6.0 (1.8)% in the pollen season. Heavy exercise challenge tests in extreme conditions increased FEV(1) post-exercise, while PEF decreased as compared with pre-exercise values. Thus, even small postexercise falls in FEV(1) may be considered as deviate exercise responses in elite athletes.