Oxygen consumption (Vo2, litres/min), carbon dioxide production (Vco2, litres/min), and respiratory exchange ratio (RER) measured with a Cosmed K4 RQ and an Airspec QP9000 mass spectrometer at rest and at different exercise levels (8, 10, 12, 14, 16, and 18 km/h) in nine male footballers
| Cosmed K4 RQ | Airspec QP9000 | |||||
|---|---|---|---|---|---|---|
| Exercise level | Vo2 | Vco2 | RER | Vo2 | Vco2 | RER |
| Values are expressed as mean (SD). | ||||||
| Rest | 0.27 (0.10) | 0.20 (0.08) | 0.74 (0.08) | 0.29 (0.16) | 0.21 (0.09) | 0.72 (0.07) |
| 8 | 2.26 (0.31) | 1.87 (0.23) | 0.83 (0.05) | 2.15 (0.37) | 1.85 (0.29) | 0.86 (0.06) |
| 10 | 2.72 (0.33) | 2.38 (0.21) | 0.88 (0.04) | 2.61 (0.34) | 2.29 (0.28) | 0.88 (0.05) |
| 12 | 3.12 (0.24) | 2.82 (0.17) | 0.90 (0.06) | 3.06 (0.26) | 2.78 (0.29) | 0.91 (0.06) |
| 14 | 3.39 (0.32) | 3.34 (0.21) | 0.99 (0.12) | 3.21 (0.42) | 3.04 (0.33) | 0.95 (0.07) |
| 16 | 3.64 (0.19) | 3.63 (0.37) | 1.00 (0.11) | 3.59 (0.31) | 3.52 (0.33) | 0.98 (0.09) |
| 18 | 3.72 (0.18) | 4.05 (0.39) | 1.09 (0.09) | 3.80 (0.36) | 4.03 (0.46) | 1.06 (0.07) |