Table 1 Participant characteristics and exercise parameters:

Age (years)

61.8 (25.2)

63.1 (8.5)

59.4(12.6)

0.4

Pack years smoked

50.5(23.3)

54.1(25.6)

43.7(17.6)

0.3

BMI (kg.m^-2)

23.3 (5.0)

24.1(3.5)

21.7(7.1)

0.3

FFMI (kg.m^-2)

16.1(2.0)

16.3 (1.6)

15.5 (2.8)

0.4

Lung function

FEV₁ %predicted

40.8(23.1)

45.8 (25.2)

31.6 (15.9)

0.17

FVC %predicted

85.1(29.3)

93.1 924.8)

70.1 (11.6)

0.07

TLC %predicted

131.4(17.5)

130.3 (16.5)

133.3 (20.4)

0.7

RV/TLC

58.2(9.2)

57.5 (8.0)

59.6 (11.7)

0.6

FRC %predicted

182.0(41.2)

177.9 (35.5)

189.6 (52.4)

0.5

TLco_c %predicted

39.6(16.4)

45.4 (16.3)

30.0 (10.9)

0.03*

Kco_c %predicted

45.9(18.7)

51.8 (19.0)

34.9 (12.9)

0.04*

PaCO₂ (kPa)

4.9(0.6)

4.7 (0.6)

5.2 (0.4)

0.06

PaO₂ (kPa)

9.9(1.1)

9.8 (1.1)

10.0 (1.2)

0.7

Muscle strength

PImax (cmH₂O)

53.7(21.2)

50.7 (18.0)

58.5(26.1)

0.4

PEmax (cmH₂O)

80.9(26.3)

77.5(27.4)

86.4(25.2)

0.5

SnPdi (cmH₂O)

94.2(16.1)

92.7(12.3)

97.0(22.5)

0.6

Cough Pgas (cmH₂O)

241.0(60.3)

242.7(66.3)

237.6(49.5)

0.9

TwT10Pgas (cmH₂O)

51.3 (27.1)

47.7 (24.5)

58.1(31.8)

0.4

TwPdi (cmH₂O)

17.0 (6.4)

17.4 (6.2)

16.2 (6.9)

0.7

QMVC (kg)

32.3 (9.6)

32.1 (10.0)

32.6 (9.5)

0.9

Exercise parameters

Peak VO₂ (ml.kg^-1/min)

11.5 (3.3)

12.1 (3.3)

10.4 (3.0)

0.2

Peak VCO₂ (ml.kg^-1/min)

11.1 (3.9)

11.6 (4.2)

10.1 (3.2)

0.4

Peak workload (W)

53.5(15.9)

57.0 (16.7)

47.0 (13.0)

0.16

Peak VE (l/min)

29.9 (9.2)

32.3 (9.4)

25.5 (7.6)

0.09

Rest EELV (l)

5.97(1.65)

5.84 (1.5)

6.22 (2.0)

0.6

Peak EELV (l)

6.62(1.95)

6.46 (1.9)

6.91 (1.1)

0.6

Δ EELV (%)

10.4 (8.2)

9.7 (6.1)

11.6 (11.6)

0.7

Δ TwPdi (%)

2.2. (15.9)

+7.7 (14.9)

-7.9 (13.2)

0.02*

Δ TwT10Pgas (%)

-7.2 (15.6)

0.3 (10.8)

-21.3 (13.5)

<0.001*