Comparison of physiological measures obtained using the Lode Excalibur Sport cycle ergometer and Tacx i-Magic home training device.

Background: The aim of this study was to compare several physiological measures obtained using a criterion cycle ergometer (Lode Excalibur Sport) and a commercially-available home training device (Tacx i-Magic).

Methods: In a randomized, counterbalanced order, eight male amateur club level cyclists (age 30.4±3.5 years, body mass 75.8±8.1 kg, stature 1.75±0.06 m) completed a submaximal and maximal incremental test on both the Lode Excalibur Sport and the Tacx i-Magic.

Results: Data from the submaximal incremental test revealed that HR was significantly greater during the Lode trials at power outputs of 250 W (P=0.003), 280 W (P<0.001), and 310 W (P<0.001). V̇O2 was significantly greater during the Lode trials at 310 W (P=0.001) and blood lactate was significantly greater during the Lode trials at 310 W (P=0.004). RER was significantly greater during the Lode trials at 310 W (P<0.001). The power output corresponding to the lactate threshold (POLT) was not significantly different between the ergometers (P>0.05). The power output corresponding to a blood lactate concentration of 4 mmol/L (PO4), was significantly greater (P=0.003) during the Tacx trials. V̇O2max was not different between the ergometers (P>0.05), however, the power output associated with V̇O2max (POV̇O2max) (P=0.02), and peak power output (PPO) (P=0.006), were significantly different.

Conclusions: Cyclists should exercise caution when transferring laboratory based physiological measures to the Tacx i-Magic during exercise >250 W.