TABLE 1

Study compliance with guideline specification [5]

First author (year) [ref.]	Study population	Medication restriction		Exercise intensity		Exercise duration		Environmental conditions		Post-challenge spirometry		Diagnostic threshold
Hallstrand (2018) [5] (ERS indirect brinchial challenge testing technical standard)		SABA, 8 h; LABA, 36 h; LABA in combination with an ICS, 36 h; ultra-LABA, 48 h; ICS, 6 h; long-acting ICS, 24 h; leukotriene receptor antagonists, 4 days; leukotriene synthesis inhibitors, 12/16 h; antihistamines, 72 h; short-acting muscarinic acetylcholine antagonist 12 h; long-acting muscarinic acetylcholine antagonist, 72 h; cromones, 4 h; xanthines, 24 h; caffeine, 24 h; vigorous exercise, 4 h.		Target ventilation is 60% of maximum (MVV or FEV₁×40) or HR >85% of maximum can serve as a surrogate for ventilation target		Maintain target ventilation for ≥4 min, preferably 6 min		Inspired air should be dry and ambient temperature <25°C This can be accomplished by conducting the study in an air-conditioned room (with ambient temperature at 20–25°C) with low RH (≤50%) An ideal system delivers dry air through a mouthpiece and a two-way valve from a talc-free reservoir filled with medical-grade compressed air		Serial assessments of spirometry for 30 min after exercise		≥10% fall in FEV₁
Eggleston (1979) [8]	n=45; age range 16–30 years; young adults with asthma	SABA, 8 h; LABA, 12 h; corticosteroid therapy was continued; cromones, 14 days.	−	Treadmill speed and slope adjusted to maintain 90% predicted HR	+	5 min treadmill running	+	No information provided	?	1, 5, 10, 15 and 20 min after exercise	−	No information provided	?
Lin (1991) [9]	n=22; age range 20–40 years; stable unmedicated asthma	Bronchodilators, 7 days; corticosteroids, 28 days; cromones, 28 days; methylxanthine, 7 days; antihistamine, 7 days	?	Treadmill rate and slope adjusted to achieve 90% predicted HR	+	6 min treadmill running	+	No information provided	?	5, 10, 15, 20, 25 and 30 min after exercise	+	>20% fall in FEV₁	−
Avital (2000) [10]	n=135; age mean±sd 12.4±3.9 years; children and young adults with asthma	Bronchodilators, 12 h; ICS was continued; cromones (sodium cromoglycate), 20 h; xanthines, NA.	−	Treadmill at 10° slope and 5 km·h⁻¹ speed	−	6 min of treadmill running	+	Temperature ranged 22–26°C and 48–56% RH	−	1, 3, 5, 10, and 15 min after exercise	−	≥8.2% fall in FEV₁	−
Klepac-Pulanic (2004) [11]	n=35; age range 15–48 years; asthma or allergic rhinitis	SABA, 12–48 h; ICS, therapy was continued; short-acting muscarinic acetylcholine antagonist (ipatropium), 24 h; xanthines (theophyllines) 72 h; antihistamines, 4 days; caffeine, on day of study; cromones; NA	−	Treadmill speed and slope adjusted to maintain 85% predicted HR	+	6 min treadmill running	+	Temperature ranged 18–28°C mean±sd 24.1±3°C and humidity 40–85% RH mean±sd 62.35±14.3% RH	−	Immediately and 3, 5, 7, 10, 15, 20 and 30 min after exercise	+	≥10% fall in FEV₁	+
Kersten (2009) [12]	n=25; mean±sd age 12.4±2 years; children with allergic asthma and EIB	SABA, 8 h; LABA, 24 h; corticosteroids, 28 days; antihistamines, 14 days; cromones, 14 days; anticholinergics, 14 days; ICS, 24 h; vigorous exercise, 4 h	−	Treadmill speed adjusted to maintain 90% predicted HR	+	≤6 min treadmill running	+	Cold, dry air was obtained by testing in an ice rink with a constant temperature of 18°C	+	1, 3, 6, 9, 12, 15 and 20 min after exercise	−	>15% fall in FEV₁	−

SABA: short-acting β₂-agonist; LABA: long-acting β₂-agonist; ICS: inhaled corticosteroid; MVV: maximum voluntary ventilation; FEV₁: forced expiratory volume in 1 s; HR: heart rate; RH: relative humidity; −: criteria not met; +: criteria met; ?: insufficient information provided; NA: not applicable; EIB: exercise-induced bronchoconstriction.