Table 1.

Classification of EIB severity^a.

Degree of EIB severity	Maximum fall in FEV1 after exercise
No EIB	<10%
Mild EIB	≥10% but <25%
Moderate EIB	≥25% but <50%
Severe EIB	≥50% for steroid-naïve patients
	≥30% for steroid-treated patients

^aEIB severity classification, adopted from Anderson et al. (12).