. 2021 Nov 20;42(1):43–52. doi: 10.1111/cpf.12734

Table 3.

Cardiorespiratory parameters recorded at rest as well as during exercise performed below and above the ventilatory threshold (VT) with and without a surgical mask

	Condition	Rest	WR_VT −25%	WR_VT +25%
TV (mL min⁻¹) ^a , ^c	Mask	550.3 ± 242.3	1873.4 ± 425.3	2178.4 ± 499.4 ^d
TV (mL min⁻¹) ^a , ^c	No mask	569.4 ± 205.3	1907.2 ± 414.2	2394.0 ± 535.5
RR (cpm) ^a , ^c	Mask	11.6 ± 3.5 ^d	26.1 ± 5.2 ^d	39.9 ± 7.7 ^d
RR (cpm) ^a , ^c	No mask	13.9 ± 3.7	28.0 ± 4.5	50.1 ± 9.9
Ve/VO₂ ^a , ^c	Mask	25.5 ± 3.1	23.1 ± 2.5 ^d	28.5 ± 3.7 ^d
Ve/VO₂ ^a , ^c	No mask	26.9 ± 3.8	24.1 ± 2.6	33.5 ± 3.9
Ve/VCO₂ ^a , ^c	Mask	32.9 ± 5.6	24.9 ± 3.4 ^d	27.0 ± 3.9 ^d
Ve/VCO₂ ^a , ^c	No mask	34.2 ± 7.4	26.2 ± 3.7	31.9 ± 4.1
FETO₂ (%) ^a , ^b , ^c	Mask	16.4 ± 0.5	15.9 ± 0.6 ^d	16.9 ± 0.6 ^d
FETO₂ (%) ^a , ^b , ^c	No mask	16.6 ± 0.5	16.2 ± 0.5	17.5 ± 0.4
FETCO₂ (%) ^a , ^b , ^c	Mask	3.9 ± 0.5	4.7 ± 0.6 ^d	4.3 ± 0.6 ^d
FETCO₂ (%) ^a , ^b , ^c	No mask	3.8 ± 0.5	4.5 ± 0.6	3.6 ± 0.5
O₂ pulse (mL/beat) ^a , ^b , ^c	Mask	3.5 ± 0.8	13.8 ± 3.2 ^d	16.3 ± 3.5 ^d
O₂ pulse (mL/beat) ^a , ^b , ^c	No mask	3.7 ± 0.8	14.6 ± 3.3	18.8 ± 4.6

Values are mean ± SD.

Abbreviations: FETCO₂, end‐tidal fractional carbon dioxide concentration; FETO₂, end‐tidal fractional oxygen concentration; RR, respiratory rate; TV, tidal volume; Ve/VCO₂, ventilatory equivalent for carbon dioxide; Ve/VO₂, ventilatory equivalent for oxygen.

^{^a}

Time main effect (p < 0.05).

^{^b}

Condition main effect (p < 0.05).

^{^c}

Condition x time interaction (p < 0.05).

^{^d}

Significant differences between conditions (p < 0.01).