Attendees to PressCamp last week were all abuzz with the new PowerCal product announcement from CycleOps. Touted as an introductory level power training product, PowerCal uses your heart rate information to calculate your power output on the bike.
The PowerCal is basically a heart rate strap with a tiny computer that uses proprietary algorithms to calculate your power output based on your heart rate during your ride. To calibrate the PowerCal computer, you must first take a 20 minute test at your local bike shop, where measurements are taken of your heart rate and power output from a real power meter. This data is then transferred to the PowerCal heart rate strap computer via an ANT+ USB stick.
The question is, can a strong correlation between heart rate and power output be proven? CycleOps seems to believe there is a strong correlation, at least while riding on a trainer indoors. The company is currently working with CU Boulder to determine the real accuracy, which they claim is around 5-10%.
The correlation problem comes when you hit the outdoors and you have hills, wind, heat, and many more variables to contend with. Supposedly CycleOps has analyzed thousands of ride data to try and establish the common deviations between heart rate and power output in order to work that into the algorithm. I am curious whether the algorithm takes into account days where you have had too much caffeine or are tired and your heart rate is naturally higher?
The PowerCal heart rate strap is ANT+ compatible so can transfer both heart rate and power output data to your ANT+ cycling computer. Your power in watts and kilojoules shows up next to the rest of your ride data for help with meeting your training goals.
At only $199, the PowerCal is a more affordable way for cyclists to start playing around with power based training. The CycleOps PowerCal will be available in the October/November time frame.
Do you think heart rate is a good indication of your power output on the bike?