Table 2.

Normative Reference Values and Ranges for Physiologic and Symptom Responses at the Tvent During Symptom-Limited Incremental CPET According to Participant Sex

CPET Parameter	Total Sample (N = 96)		Men (n = 47)		Women (n = 49)
	Mean ± SD	LLN-ULN	Mean ± SD	LLN-ULN	Mean ± SD	LLN-ULN
$\dot{\mathrm{V}}$O2 at Tvent, L/min	0.95 ± 0.31	0.51-1.56	1.11 ± 0.28	0.75-1.60	0.80 ± 0.25	0.49-1.23
$\dot{\mathrm{V}}$O2 at Tvent, mL/kg/min	12.6 ± 3.9	7.7-18.3	13.7 ± 3.9	8.7-21.2	11.6 ± 3.6	6.6-16.3
$\dot{\mathrm{V}}$O2 at peak, L/min	2.01 ± 0.58	1.20-2.96	2.38 ± 0.51	1.63-3.40	1.66 ± 0.40	1.05-2.23
$\dot{\mathrm{V}}$O2 at peak, mL/kg/min	26.7 ± 7.2	17.0-42.7	28.8 ± 6.7	20.5-43.0	24.5 ± 7.2	16.0-37.5
$\dot{\mathrm{V}}$O2 at Tvent, %$\dot{\mathrm{V}}$O2 peak	48.3 ± 10.6	32.6-65.6	47.6 ± 9.5	31.6-63.0	49.0 ± 11.6	32.8-65.7
$\dot{\mathrm{V}}$O2 at Tvent, % predicteda$\dot{\mathrm{V}}$O2 peak	51.2 ± 13.5	32.9-75.4	48.5 ± 11.2	33.5-67.2	53.8 ± 15.1	33.1-82.0
$\dot{\mathrm{V}}$CO2, L/min	0.83 ± 0.31	0.41-1.39	0.98 ± 0.28	0.64-1.45	0.69 ± 0.27	0.35-1.14
RER	0.85 ± 0.10	0.69-1.02	0.86 ± 0.09	0.72-0.99	0.84 ± 0.11	0.68-1.03
Power output, W	51 ± 24	16-94	60 ± 23	29-97	42 ± 20	15-71
HR, beats/min	101 ± 16	77-123	100 ± 19	75-121	102 ± 13	84-123
Oxygen pulse, mL O2/beat	9.5 ± 3.0	5.5-14.6	11.2 ± 2.9	7.5-14.8	7.8 ± 2.0	5.3-11.1
BP, mm Hg
Systolic	147 ± 32	112-188	153 ± 32	117-188	142 ± 31	105-187
Diastolic	77 ± 14	62-95	77 ± 14	61-95	76 ± 14	65-93
$\dot{\mathrm{V}}$e/$\dot{\mathrm{V}}$CO2	30.2 ± 3.8	25.1-37.9	29.2 ± 2.7	25.4-33.9	31.2 ± 4.5	25.2-39.5
$\dot{\mathrm{V}}$e/$\dot{\mathrm{V}}$O2	25.8 ± 3.3	20.8-32.3	25.5 ± 3.0	21.4-31.6	26.2 ± 3.6	20.7-32.3
PETCO2, mm Hg	40.6 ± 4.2	34.5-47.1	41.0 ± 4.4	35.1-47.5	40.2 ± 4.1	34.5-46.8
PETO2, mm Hg	101.6 ± 7.7	90.6-111.4	100.8 ± 9.1	89.3-112.4	102.2 ± 6.0	93.4-111.0
SpO2, %	97 ± 2	95-99	97 ± 3	94-99	98 ± 1	96-99
$\dot{\mathrm{V}}$e, L/min	24.4 ± 8.0	13.7-38.7	28.2 ± 7.3	18.7-40.7	20.8 ± 6.8	12.1-34.3
$\dot{\mathrm{V}}$e, % MVV	24 ± 8	14-36	25 ± 8	14-36	24 ± 8	14-37
VT, L	1.22 ± 0.36	0.68-1.88	1.41 ± 0.31	0.98-2.02	1.04 ± 0.31	0.62-1.50
VT, % IC	41.5 ± 9.7	25.8-61.0	43.0 ± 8.3	29.0-60.7	40.1 ± 11.2	25.0-60.6
Bf, breaths/min	20 ± 4	16-94	20 ± 4	15-27	21 ± 5	13-28
IC, L	2.98 ± 0.67	2.01-4.01	3.34 ± 0.66	2.10-4.17	2.63 ± 0.46	2.01-3.52
IRV, L	1.76 ± 0.56	0.90-2.66	1.93 ± 0.61	0.94-2.84	1.59 ± 0.45	0.89-2.36
EILV, L	4.20 ± 0.97	2.82-5.78	4.77 ± 0.93	3.21-6.53	3.69 ± 0.68	2.68-4.74
EELV, L	2.98 ± 0.80	1.86-4.42	3.35 ± 0.84	2.06-4.57	2.66 ± 0.61	1.78-3.73
EILV, % TLC	70 ± 7	58-82	70 ± 8	58-83	69 ± 6	61-81
EELV, % TLC	49 ± 7	38-62	49 ± 8	36-60	50 ± 6	39-62
Breathlessness, Borg 0-10	1 ± 1	0-3	1 ± 1	0-3	1 ± 1	0-3
Leg discomfort, Borg 0-10	1 ± 1	0-3	2 ± 1	0-4	1 ± 1	0-3

Bf = breathing frequency; CPET = cardiopulmonary exercise testing; EELV = end-expiratory lung volume; EILV = end-inspiratory lung volume; HR = heart rate; IC = inspiratory capacity; IRV = inspiratory reserve volume; LLN = lower limit of normal; MVV = maximum voluntary ventilation; P_ETCO₂ = end-tidal Pco₂; P_ETO₂ = end-tidal Po₂; RER = respiratory exchange ratio; SpO₂ = peripheral oxygen saturation; TLC = total lung capacity; Tvent = ventilatory threshold; ULN = upper limit of normal; $\dot{\mathrm{V}}$CO₂ = rate of CO₂ production; $\dot{\mathrm{V}}$_e = minute ventilation; $\dot{\mathrm{V}}$_e/$\dot{\mathrm{V}}$CO₂ = ventilatory equivalent for CO₂; $\dot{\mathrm{V}}$_e/$\dot{\mathrm{V}}$O₂ = ventilatory equivalent for oxygen; $\dot{\mathrm{V}}$O₂ = rate of oxygen consumption; V_T = tidal volume.

^aPredicted using reference equations by Lewthwaite et al.¹¹