Table 2. Between group comparisons for cardiopulmonary exercise test variables at rest and peak exercise.

	Rest		Peak Exercise
	CTL	CF	CTL	CF
Total exercise duration, seconds	-	-	960 ± 41	729 ± 48*
Workload, watts	-	-	179 ± 11	100 ± 9*
RPE (6-20, Borg)	6.0 ± 0.0	6.0 ± 0.0	17.5 ± 0.2†	16.8 ± 0.3†
Cardiac hemodynamics
SVI, mL/m2	40 ± 3	31 ± 3*	51 ± 2†	45 ± 3
QI, L/min/m	3.1 ± 0.2	2.6 ± 0.2*	9.1 ± 0.3†	6.7 ± 0.5*†
Ventilation or gas exchange
VO2, mL/kg/min	5.9 ± 0.3	6.5 ± 0.4	33.2 ± 2 .0†	22.6 ± 2 .2* †
VO2, L/min	0.4 ± 0.0	0.4 ± 0.0	2.3 ± 0.1†	1.4 ± 0.1* †
VCO2, L/min	0.3 ± 0.0	0.4 ± 0.0	26 ± 0.2†	1.6 ± 0.2 * †
RR, breaths/min	19 ± 2	22 ± 1	38 ± 2†	36 ± 2
VE, L/min	14 ± 1	16 ± 1	82 ± 4	56 ± 3* †
VT, L	0.8 ± 0.05	0.8 ± 0.07	2.2 ± 1.2	1.6 ± 1.2*
PETCO2, mm Hg	30 ± 1	30 ± 1	35 ± 1	36 ± 1
Ca-vO2, mL/100 mL/m2	5.8 ± 0.7	6.4 ± 1.1	15.7 ± 1.0†	13.3 ±l.8†
SaO2, %	97.8 ± 0.3	95.7 ± 0.4*	96.9 ± 0.3	93.8 ± 1.2*
Heart rate or blood pressure
HR, beats/min	81 ± 3	93 ± 4*	177 ± 2 †	145 ± 7* †
SBP, mm Hg	110 ± 2	106 ± 2	158 ± 4†	142 ± 6* †
DBP, mm Hg	71 ± 1	70 ± 2	61 ± 4	67 ± 4
MAP, mm Hg	84 ± 1	82 ± 2	93 ± 3†	92 ± 4

Data are presented as mean ± SEM. CTL, control (n = 25); CF, cystic fibrosis (n = 17); RPE, rate of perceived exertion; SV_I, stroke volume index; Q_I, cardiac index; VO₂, oxygen uptake; VCO₂, carbon dioxide output; RR, respiratory rate; V_E, minute ventilation; V_T, tidal volume; P_ETCO₂, end-tidal partial-pressure carbon dioxide; C_a-vO₂, arterial-mixed venous oxygen content difference; SaO₂, peripheral oxygen saturation; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure. Between group comparisons were performed using Wilcoxon rank-sum tests for all variables. Within group comparisons were performed using paired Student's t-tests.

^*p<0.05, CTL vs. CF.

^†p<0.05, rest vs. peak exercise.