Table 3.
Cardiorespiratory responses during submaximal and maximal exercise.
| Variables | Rest | Submaximal 1 | Submaximal 2 | |||
|---|---|---|---|---|---|---|
| Nonobese | Obese | Nonobese | Obese | Nonobese | Obese | |
| Work Rate (W) | – | – | 27 ± 13 | 24 ± 14 | 53 ± 22 | 49 ± 28 |
| V̇O2 (L/min) | 0.23 ± 0.06 | 0.30 ± 0.07Ω | 0.68 ± 0.18 | 0.86 ± 0.26Ω | 0.96 ± 0.30 | 1.17 ± 0.42* |
| %V̇O2max | 18 ± 6 | 21 ± 7 | 53 ± 11 | 56 ± 13 | 74 ± 11 | 72 ± 11 |
| V̇E (L/min) | 10.56 ± 4.33 | 12.57 ± 3.51* | 26.22 ± 6.42 | 30.81 ± 7.48* | 40.19 ± 10.50 | 44.07 ± 12.50 |
| VT (L) | 0.96 ± 0.33 | 0.83 ± 0.25 | 1.24 ± 0.27 | 1.39 ± 0.58 | 1.48 ± 0.41 | 1.65 ± 0.74 |
| Fb (bpm) | 14.47 ± 4.03 | 15.37 ± 5.13 | 22.93 ± 7.07 | 24.77 ± 9.14 | 29.11 ± 9.40 | 28.95 ± 7.74 |
| VE/VCO2 | 58.07 ± 11.37 | 53.53 ± 11.09 | 45.30 ± 10.37 | 42.26 ± 8.81 | 43.37 ± 8.79 | 41.33 ± 8.71 |
| PETCO2 (Torr) | 36 ± 6 | 37 ± 6 | 38 ± 6 | 40 ± 5 | 37 ± 6 | 39±5Ω |
| RER | 0.80 ± 0.09 | 0.79 ± 0.12 | 0.89 ± 0.11 | 0.85 ± 0.13 | 1.0 ± 0.09 | 0.95 ± 0.09* |
| CO (L/min) | 3.57 ± 1.02 | 4.28 ± 1.08* | 6.84 ± 1.72 | 8.81 ± 2.61Ω | 8.19 ± 2.30 | 10.05 ± 2.92* |
| CI | 2.2 ± 0.5 | 2.1 0.5 | 4.0 ± 0.8 | 4.3 ± 1.2 | 4.8 ± 1.1 | 4.7 ± 1.2 |
| HR (bpm) | 83 ± 20 | 80 ± 16 | 103 ± 22 | 98 ± 19 | 126 ± 28 | 112 ± 24* |
| HR (%Pred) | 48 ± 9 | 47 ± 9 | 60 ± 11 | 57 ± 9 | 73 ± 13 | 66 ± 12* |
| SV (ml) | 45 ± 15 | 56 ± 16* | 69 ± 22 | 91 ±26Ω | 67 ± 23 | 92 ± 25Ω |
| SVI | 25 ± 6 | 28 ± 8 | 38 ± 10 | 46 ± 11* | 36 ± 9 | 45 ± 11* |
| a-vO2 Diff (%) | 6.66 ± 1.70 | 7.46 ± 2.01 | 10.32 ± 2.65 | 10.00 ± 2.70 | 12.08 ± 2.40 | 11.78 ± 3.14 |
| Lactate (mmol) | 1.57 ± 0.69 | 1.33 ± 0.61 | 2.04 ± 0.79 | 2.35 ± 0.73 | 3.73 ± 1.28 | 2.92 ± 1.36* |
| IC (L) | 2.27 ± 0.67 | 2.79 ± 0.81† | 2.38 ± 0.75 | 2.79 ± 0.96 | 2.39 ± 0.80 | 2.74 ± 0.94 |
| RPB (0–10) | 1.1 ± 1.3 | 1.5 ± 2.0 | 2.4 ± 1.4 | 3.2 ± 2.2* | 4.4 ± 1.8 | 4.9 ± 2.2 |
| RPE (6–20) | – | – | 10.2 ± 2.4 | 11.7 ± 3.0* | 13.4 ± 2.5 | 13.9 ± 2.5 |
Data are mean ± SD,
p < 0.05;
p<0.01;
p<0.001.
V̇O2=oxygen uptake in L/min; V̇E=minute ventilation in L/min; VT=tidal volume in L; Fb=breathing frequency in beat per minute (bpm); V̇E/ V̇CO2=ventilatory equivalent for carbon dioxide; PETCO2=end-tidal carbon dioxide in Torr; RER=respiratory exchange quotient; CO=cardiac output in L/min; CI=cardiac index; HR=heart rate in beats per minute (bpm); HR (%Pred)= heart rate as a percent of predicted maximal heart rate; SV=stroke volume in ml; SI=stroke volume index; a-vO2 Diff=arterial-mixed venous oxygen difference in %; IC=inspiratory capacity in L; RPB=ratings of perceived breathlessness using the Borg 0–10 scale; and RPE=ratings of perceived exertion using the Borg 6–20 scale.