Table 2.

Mean values with and without SMs during the 30 min continuous tests (n = 13; excluding the warm-up and recovery phase).

	Co	SM	p-value	n2p	DIET
Pulmonary parameters
${\text{VO}}_2$(ml min−1 kg−1)	34.49 ± 5.79	33.05 ± 4.96	0.04*	0.31	44.79 ± 9.12
${\dot{\text{V}}\text{CO}}_2$ (ml min−1)	2685 ± 278	2575 ± 310	0.04*	0.30	3958 ± 560
VE (l min−1)	82.42 ± 10.66	77.05 ± 9.26	< 0.01*	0.61	141.83 ± 22.73
${\text{V}}_E/\dot{V}{\text{O}}_2$ (l min−1/l min−1)	29.34 ± 4.41	28.50 ± 3.42	0.19	0.14	38.75 ± 7.12
${\text{V}}_E/\dot{V}{\text{CO}}_2$ (l min−1/l min−1)	30.80 ± 3.81	30.01 ± 3.33	0.26	0.10	35.90 ± 3.87
${\dot{\text{V}}}_{\text{A}}$ (l min−1)	60.88 ± 7.48	57.38 ± 6.55	0.01*	0.42	102,65 ± 17,71
Ti (s)	0.89 ± 0.14	1.01 ± 0.13	< 0.01*	0.73	0.63 ± 0.11
Te (s)	0.98 ± 0.21	0.95 ± 0.17	0.14	0.17	0.66 ± 0.17
VT (l)	2.49 ± 0.35	2.45 ± 0.36	0.48	0.04	2.98 ± 0.59
RR (bpm)	34.03 ± 7.29	32.09 ± 5.40	0.02*	0.37	49.08 ± 11.23
Hemodynamic parameters
SBP (mmHg)	172.3 ± 15.8	177.2 ± 17.6	0.33	0.08	210.4 ± 26.9
DBP (mmHg)	74.6 ± 6.4	72.3 ± 9.1	0.20	0.13	77.5 ± 13.7
CO (l min−1)	25.93 ± 4.04	28.59 ± 3.94	0.06	0.27	32.06 ± 4.62
SV (ml)	168.4 ± 30.87	178.8 ± 25.67	0.22	0.12	176.02 ± 26.91
HR (bpm)	154.5 ± 11.4	160.1 ± 11.2	< 0.01*	0.59	183.0 ± 11.4
CW (J)	29,049 ± 6165	31,866 ± 6770	0.14	0.17	37,040 ± 6964
avDO2 (%)	11.11 ± 1.84	9.59 ± 1.44	0.02*	0.38	11.74 ± 2.13
LAC∆ (mmol l−1)	4.27 ± 1.46	4.71 ± 1.42	0.26	0.11	9.01 ± 1.79
RER	0.95 ± 0.05	0.95 ± 0.05	0.97	–	1.08 ± 0.11
RPE (1–10)	6.6 ± 1.1	6.9 ± 1.1	0.16	0.16	10
SO2 (%)	95.22 ± 0.71	95.32 ± 0.83	0.73	0.01	–
Mean power output (Watt)	202.7 ± 26.0	202.7 ± 26.0	1.0	–	300.71 ± 40.52
Exercise duration (min)	30 ± 0	30 ± 0	1.0		–

Values are given as the means and standard deviations. The values are presented as means and standard deviations.

DIET double incremental exercise test; Co control; SM surgical mask; IET incremental exertion test; ${\text{VO}}_2$ oxygen uptake; $\dot{V}C{O}_2$ carbon dioxide production; V_E minute ventilation; $V_E/V{O}_2$ refers to the number of liters of ventilation per liter of oxygen consumed; $V_E/\dot{V}C{O}_2$ refers to the number of liters of ventilation per liter of carbon dioxide ${\dot{\text{V}}}_A$ alveolar ventilation; RR respiratory rate; V_T tidal volume; T_i inspiratory time; T_e expiratory time; SBP systolic blood pressure (5-min interval); DBP diastolic blood pressure (5-min interval); SV stroke volume; CO cardiac output; HR heart rate; avDO₂ arteriovenous oxygen difference; RER respiratory exchange ratio, LAC blood lactate concentration (5-min interval); SO₂% oxygen saturation RPE rating of perceived exertion (5-min interval); n²_p.

*Significant differences from control.