Anti-doping Policy, Therapeutic Use Exemption and Medication Use in Athletes with Asthma: A Narrative Review and Critical Appraisal of Current Regulations

Table 1 Objective testing accepted by the World Anti-Doping Agency to diagnose asthma in athletes

Diagnostic methods	Criteria
Bronchodilator reversibility	≥ 12% increase in FEV₁^a
Bronchoprovocation challenge(s):
Direct
Methacholine/histamine	≥ 20% reduction in FEV₁
Indirect
Exercise challenge (laboratory and field-based)	≥ 10% reduction in FEV₁^c
Eucapnic voluntary hyperpnoea (EVH)^b	≥ 10% reduction in FEV₁^c
Dry powder mannitol	≥ 15% reduction in FEV₁
Hypertonic saline (4.5%)	≥ 15% reduction in FEV₁

FEV₁ forced expiratory volume in one second, IOC-MC International Olympic Committee—Medical Commission
^aSupports asthma diagnosis
^bOptimal test to detect asthma in athletes (IOC-MC)
^cSustained reduction in FEV₁ required (i.e. two consecutive timepoints) to confirm diagnosis