. Author manuscript; available in PMC: 2023 Aug 1.

Published in final edited form as: J Physiol. 2022 Jul 7;600(16):3671–3688. doi: 10.1113/JP283051

Table 4.

Pulmonary gas exchange and cardiorespiratory responses to normoxia and hyperoxic hypercapnia at rest and during passive leg movement (LM) in women

	Normoxia		Hyperoxic hypercapnia		p value

	Rest	LM	Rest	LM	Main effect of LM	Main effect of hypercapnia	Interaction effect
Pulmonary gas exchange
S_pO₂ (%)	97 ± 1	97 ± 1	100 ± 0^†	100 ± 1^†	0.748	<0.001	0.596
P_ETO₂ (mmHg)	85 ± 3	83 ± 5	519 ± 20^†	522 ± 15^†	0.633	<0.001	0.098
P_ETCO₂ (mmHg)	32 ± 4	33 ± 1	43 ± 2^†	43 ± 2^†	0.732	<0.001	0.394
Ventilatory responses
V̇_E (L·min⁻¹)	9 ± 2	11 ± 2	24 ± 12^†	28 ± 9^*^†	0.010	<0.001	0.282
f_B (breaths·min⁻¹)	15 ± 5	17 ± 4^*	19 ± 8^†	21 ± 6^†	0.049	0.009	0.420
V_T (L)	0.7 ± 0.2	0.6 ± 0.1	1.3 ± 0.2^†	1.4 ± 0.3^†	0.388	<0.001	0.094
Hemodynamic responses
MAP (mmHg)	100 ± 17	95 ± 23^*	101 ± 17	102 ± 18^†	0.172	0.024	0.029
HR (beats·min⁻¹)	66 ± 10	75 ± 15^*	72 ± 14^†	81 ± 15^*^†	<0.001	0.014	0.886
SV (mL)	70 ± 14	73 ± 16	76 ± 15	78 ± 16	0.262	0.053	0.760
CO (L·min⁻¹)	4.6 ± 1.1	5.0 ± 1.1^*	5.5 ± 1.3^†	5.9 ± 1.3^*^†	0.004	0.002	0.797
LBF (L·min⁻¹)	0.5 ± 0.4	1.1 ± 0.5^*	0.5 ± 0.4	1.3 ± 0.6^*^†	<0.001	0.011	0.076
LVC (mL·min⁻¹·mmHg)	4.1 ± 2.8	11.1 ± 5.3^*	4.6 ± 2.6	12.1 ± 5.7^*	<0.001	0.122	0.380

S_pO₂: oxyhemoglobin saturation; P_ETO₂: end-tidal partial pressure of O₂; P_ETCO₂: end-tidal partial pressure of CO₂; V̇_E: minute ventilation; f_B: breathing frequency; V_T: tidal volume; MAP: mean arterial pressure; HR: heart rate; SV: stroke volume; CO: cardiac output; LBF: leg blood flow; LVC: leg vascular conductance.

p < 0.05 vs. rest;

^†

p < 0.05 vs. normoxia. Pulmonary gas exchange and ventilatory responses are 60-s average at rest and during LM, while hemodynamic responses are 60-s average at rest and the maximal response during LM; n = 12. Data were analyzed using two-way repeated-measure ANOVA with Tukey’s post hoc test and are presented as mean ± S.D.