Erg Bikes, like the Concept2 BikeErg, are increasingly popular tools for athletes and fitness enthusiasts. They offer a low-impact, effective way to train and measure performance. Understanding how these devices measure power, and the factors influencing accuracy, is crucial for effective training and data interpretation.
Recent studies have explored the physiological responses to erg bike and rowing ergometer (RowErg) workouts. Research, such as the study by Joshua R. Lindenthaler et al. in Frontiers in Physiology (2018), highlights the differences in physiological responses between rowing and cycle ergometry in elite male rowers. Another study by Kirstie J. Turner and Anthony J. Rice in the International Journal of Sports Science & Coaching (2020) specifically investigates the physiological responses on the Concept II BikeErg and RowErg in well-trained male rowers. These studies, often accessible through platforms like Academia, provide valuable insights into the effectiveness of erg bikes for training.
One key aspect of erg bike usage is the accuracy of wattage measurement. At high flywheel rotation speeds, bearing resistance becomes negligible compared to air drag. This is evidenced by the linear increase in rotation period during recovery phases, as discussed in online forums like the C2 forum. For the Concept2 RowErg, power measurement is self-calibrating. However, the calibration process for the BikeErg is different due to the continuous nature of cycling. Unlike rowing, there isn’t a natural pause in power input during cycling that allows for automatic calibration. To ensure accurate power readings on a BikeErg, it is likely necessary to briefly rest the pedals. This short pause allows the system to calibrate, leading to stable and reliable power measurements throughout a cycling session, provided the damper setting remains constant.
It’s important to recognize that both RowErgs and BikeErgs measure power at a specific point in the system. For the RowErg, the measured power does not account for the energy expended moving the body mass on the slide or power losses within the chain drive. Research by S. Boyas et al., published in the International Journal of Sports Medicine (2006), compared power measurements at the handle of a RowErg with the Concept2 system’s measurement. This study revealed a consistent difference of approximately 25W, relatively independent of the power output level, attributable to these factors. Similarly, the BikeErg measures power at its flywheel, and while it provides a consistent measure of power output at that point, users should understand that this is a measure of mechanical power delivered to the ergometer and not necessarily the gross metabolic power of the user, which would include other physiological costs.
In conclusion, erg bikes are valuable tools for exercise and performance measurement. Accurate power measurement is vital for effective training. While Concept2 RowErgs are self-calibrating, BikeErgs likely require a brief pause in pedaling for initial calibration to ensure precision. Furthermore, understanding that ergometers measure power at a specific point in the mechanical system helps users interpret data accurately and appreciate the nuances of power output during exercise.
