Vo2 requirement at different displayed power outputs on five cycle ergometer models: a preliminary study.

BACKGROUND AND AIMS

The validity of five brands of cycle ergometers was evaluated by the comparison of the Vo(2) requirements at different displayed power.

METHODS AND RESULTS

Five physically active men performed a continuous incremental exercise test on five ergometers (Ergomeca, Lifecycle, Monark, Polar S710 and CompuTrainer). The latter was also compared with a standard dynamometer in order to associate Vo(2) values with the real power. Every test started with a 5-min warm-up on the same cycle ergometer (Ergomeca) at 100 W to make sure that the Vo(2) differences do not come from Vo(2) measurement error. Only last minute steady-state Vo(2) values of each 2-min stage were used for the Vo(2)-watt curve. Large differences (5- 10 ml kg(-1) min(-1)) at the same displayed power indicate inaccuracy of displayed power output (PO). Using corrected power values from the dynamometer revealed that for the same Vo(2) the CompuTrainer underestimates PO by approximately 30 W between 100 and 300 W, whereas the Lifecycle overestimate it by 3-53 W from 100 to 300 W. The Monark and Polar S710 underestimate PO by 15 W and the Ergomeca by approximately 5 W.

CONCLUSION

Inaccuracies between -10% and 18% in displayed PO of various cycle ergometers question their interchangeability.