Table 2– Cardiopulmonary parameters at rest and during the 6-min walk test (6MWT)

Subjects n	444
FEV₁ L	2.78±0.74
FEV₁% pred	100±14
FVC % pred	102±14
S_p,O₂ % pred at rest	96.5±1.7
S_p,O₂ % pred post-6MWT	95.8±2.4^#
Respiratory rate at rest breaths·min⁻¹	16±2
HR at rest beats·min⁻¹	76±10
HR_max/HR_max % pred	73±13
End Borg dyspnoea score	0.5 (0–3)
Borg dyspnoea score after 6MWT ≥1	44
6MWD m
1st test	554±89
2nd test	565±90^¶
Best	571±90

Data are presented as mean±sd, median (5th–95th percentiles) or %, unless otherwise stated. FEV₁: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity; S_p,O₂: arterial oxygen saturaiton measured by pulse oximetry; HR: heart rate; HR_max: maximal HR; 6MWD: 6-min walk distance. ^#: S_p,O₂ decreased during the test (0.7%; p<0.001); ^¶: the walked distance during the second test was longer than the for first test (12 m; p<0.001).