***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES : To study factors affecting the occurrence of  exercise induced bronchospasm ( EIB ) in elite runners . METHODS : Fifty eight elite runners , 79 % of them belonging to Finnish national teams , volunteered . The athletes answered a question naire on respiratory symptoms . Skin prick tests were used to investigate atopy , and spirometry to examine lung function at rest and after an exercise challenge test ( ECT ) at subzero temperature in the winter and after a similar ECT in the summer at the end of the birch pollen season . RESULTS : Definitive EIB ( a post-exercise reduction of 10 % or more in forced expiratory volume in one second ( FEV1 ) was observed in five ( 9 % ) of the 58 runners . A subgroup consisting of 19 non-atopic symptom-free runners with no family history of asthma was used to establish a normal range for post-exercise reduction in FEV1 . When this group 's mean exercise induced change in FEV1 minus 2 SDs ( a reduction of 6.5 % or more in FEV1 ) was taken as the lower limit of the reference range , 15 ( 26 % ) of the runners had probable EIB in either the winter or the pollen season . The occurrence of probable EIB depended on atopy ( odds ratio increased with number of positive skin prick test reactions , p < 0.05 ) . Nine ( 22 % ) of the 41 runners , challenged in both the winter and the pollen season , had probable EIB only in the winter , and three ( 7 % ) had it only in the pollen season . Only one runner ( 2 % ) had EIB in both tests . CONCLUSIONS : Mild EIB is common in Finnish elite runners and is strongly associated with atopy . Seasonal variability affects the occurrence of EIB , and thus exercise testing should be performed in both cold winter air and the pollen season to detect EIB in elite runners To determine the effect of two forms of warm-up on postexercise bronchoconstriction in athletes with exercise-induced asthma , 12 moderately trained persons with asthma ( age = 26.5 + /- 2.2 yr ; height = 169.2 + /- 2.6 cm ; weight = 64.3 + /- 2.6 kg ; VO2max = 52.7 + /- 1.3 ml.kg-1.min-1 ) were tested under three experimental conditions ; continuous warm-up ( CW ) , interval warm-up ( IW ) , and control ( C ) . CW consisted of 15 min of treadmill running at a velocity corresponding to 60 % VO2max followed by an exercise challenge test ( ET = 6 min at 90 % VO2max ) . IW involved 8 x 30-s runs ( 1.5 min rest between bouts of exercise ) , at an intensity equivalent to 100 % VO2max , followed by an ET . C consisted of only the ET .  FEV1 , FVC , and MMEFR were measured prior to the experimental conditions , repeated before the ET , and every 2 min during a 25-min passive recovery period , using a Breon spirometer . Postexercise changes in pulmonary function were recorded as the largest decrese in FEV1 , FVC , and MMEFR during the recovery period , and expressed as a percentage of baseline values . Significant differences were detected in % FEV1 ( 34 . 6,16.7,29.7 : P = 0.009 ) , % FVC ( 30.0,10.7,21.0 : P = 0.03 ) , and % MMEFR ( 50.0,30.2,43.4 : P = 0.05 ) , in comparing C , CW , and IW , respectively . Scheffe 's test detected significance ( P < 0.05 ) between C and CW for all three dependent variables ; no statistical significance between C and IW or IW and CW occurred . These data indicate that a continuous warm-up of 15 min at 60 % VO2max can significantly decrease postexercise bronchoconstriction in moderately trained athletes The effect of a prolonged warm-up period of exercise on subjects with exercise-induced asthma ( EIA ) has been studied . Seven asthmatic subjects with known EIA were exercised according to two different protocol s on two separate days , which were r and omized . On Day A , subjects performed a st and ard 6-min treadmill run ( S1A ) , which increased heart rate to 98 % predicted maximum , followed 45 min later by an identical run ( S2A ) . Refractoriness was demonstrated on the second exercise test , with a mean maximal fall in FEV1 of 29 + /- 3.1 % and a PEFR of 32 + /- 2.8 % after S2A , compared with a mean maximal fall in FEV1 of 46 + /- 2.6 % and a PEFR of 51 + /- 4.0 % after S1A . On Day B , subjects performed a 30-min treadmill run at a lower gradient ( W1B ) , followed 21 min later by another st and ard 6-min treadmill test ( S2B ) . W1B was followed by significantly less EIA ( mean maximal fall in FEV1 of 17 + /- 5.4 % and a PEFR of 21 + /- 6.3 % ) than followed S1A . Nevertheless , when subjects subsequently performed a st and ard 6-min run ( S2B ) , significant refractoriness to bronchoconstriction , comparable to that observed after S2A , developed , with a mean maximal fall in FEV1 of 26 + /- 3.6 % and a PEFR of 27 + /- 2.3 % ( p less than 0.05 ) . We conclude that a warm-up period of exercise can induce refractoriness to EIA without itself inducing marked bronchoconstriction There are two apparently conflicting theories on the pathogenesis of exercise-induced asthma . One view is that exercise-induced asthma is directly related to respiratory heat exchange and that mast cells are not involved . The other theory explains exercise-induced asthma on the basis of a temperature-independent release of mast-cell mediators . A theory is put forward here that airway cooling in asthmatic subjects during exercise leads directly to mast-cell degranulation and that this explains the association between exercise , respiratory heat exchange , and mediator release 
    Output:
    
CONCLUSIONS The most consistent and effective attenuation of EIB was observed with high-intensity interval and variable intensity preexercise warm-ups .
These findings indicate that an appropriate warm-up strategy that includes at least some high-intensity exercise may be a short-term nonpharmacological strategy to reducing EIB