THE COSMED K4 TELEMETRY SYSTEM AS AN ACCURATE DEVICE FOR OXYGEN-UPTAKE MEASUREMENTS DURING EXERCISE

The purpose of this study was to test the accuracy of oxygen uptake (( V) over dot O-2) measurements using the Cosmed K4 portable telemetry s ystem. This system of higher technology than the original Cosmed K2 de vice, contains a CO2 electrode allowing measurements alternatively by either the Cosmed K4 system (K4) or the CPX Medical Graphics (CPX) dur ing a maximum oxygen uptake ((V) over dot O(2)max) ergocycle test, at rest and during several submaximal exercises (25, 50 and 75% of maxima l work rate) in seven subjects, Heart rate values were comparable for exercise at the same work stage during gas collection using the two sy stems, indicating that the physiological stresses were similar, The (V ) over dot O-2 values did not significantly differ at rest (4.40 +/- 0 .83 vs 4.16 +/- 0.58 ml . min(-1) . kg(-1)), at 25% Wmax (20.97 +/- 1. 31 vs 21.32 +/- 2.54 ml . min(-1) . kg(-1)), at 50% Wmax (33.32 +/- 3. 92 vs 33.50 +/- 3.51 ml . min(-1) . kg(-1)), at 75% Wmax (47.01 +/- 7. 51 vs 47.49 +/- 7.11 ml . min(-1) . kg(-1)) and at maximal intensities (62.07 +/- 8.48 vs 62.84 +/- 11.31 ml . min(-1) . kg(-1)) using K4 an d CPX devices, respectively, The results of this study indicated that the K4 system was accurate for all oxygen uptake measurements from res t to maximum exercise levels.