A centralized spirometry data collection system was used to reduce FEV1 variability between and within patients and between each participating study center.
The percentage fall was defined as 100*(baseline-post baseline)/baseline. The baseline FEV1 is the test day FEV1 measured 5 minutes before the exercise challenge (30 minutes postdose). FEV1 post exercise challenge were measured 5 (±5), 10 (±5), 15 (±5), 30 (±5), and 60 (±10) minutes after completion of the exercise challenge.
The exercise challenge consisted of the participant running on a motor-driven treadmill (with adjustable speed and incline). The treadmill was set at a speed and incline sufficient to increase the participant's heart rate to ≥80% of the maximum rate for age (220 bpm-age in years) for a period of either 6, 7, or 8 minutes using a stepped-exercise protocol in accordance with ATS guidelines (American Thoracic Society 2000). Conditions were repeated for subsequent challenges.