Table 3Factors that may influence the severity of EIB/EIA

FactorDecrease EIB/EIAIncrease EIB/EIA
Environmental conditionsWarm temperatures (34–37° C)124
High humidity (100%)
Absence of allergens
Low air pollution
Cold temperatures, dry air 124,125
Airborne particles and pollutants, allergens, moulds, dust
Irritants: automobile exhaust, sulphur dioxide, nitrogen dioxide, smoke, ozone,126 chlorine127
Type, intensity, duration of ExerciseShort episodes of fast/slow running with brief rests128
VO2 max <40% predicted129
<3 minutes continuous exercise
Continuous activities that require near maximum aerobic capacity
VO2 max ≥60% predicted
6–8 minutes continuous exercise
Overall control of underlying asthma and BHRGood control: FEV1 >70% predicted
Fall in BHR130
Poor control: FEV1 <65% predicted
Increase in BHR130
Physical conditioningGood physical conditioning
Warmup and cooldown sessions
Poor physical conditioning
Sudden burst of activity
Emotional stress126
Athletic overtraining126
Respiratory tract infections, especially viralNo respiratory tract infectionsPresence of respiratory tract infections126
Time since last exerciseIf within 40–90 min may benefit from refractory period130>2–3 hr
Concurrent medicationsMaintenance anti-inflammatory bronchodilator medicationSalicylates, NSAIDS, β-blockers130
Pre-exercise foods eatenNonePeanuts, celery, shrimp, grain, carrots, bananas130

BHR = bronchial hyperresponsiveness

From: 1, Introduction

Cover of Exercise-Induced Bronchoconstriction and Asthma
Exercise-Induced Bronchoconstriction and Asthma.
Evidence Reports/Technology Assessments, No. 189.
Dryden DM, Spooner CH, Stickland MK, et al.

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