Mean values over 240 min for forced expiratory volume in 1 s (FEV1) (l), heart rate (bpm), SpO2 (%), dyspnoea visual analogue scale (VAS) (mm), tremor acceleration (m s−1 s−1), tremor VAS (mm), systolic (SBP) and diastolic blood pressure (DBP) (mmHg) after rac-formoterol 6 (▴), 12 (▾), 24 (♦) and 48 (▵) μg and placebo (□)