iMagic calibration by polar

For those who own a Polar HRM and an iMagic I have found an alternative way of seemingly calibrating the iMagic power setting (scale factor adjustment).

On your polar you can identify your VO2 max (OwnIndex) which will then adjust your kCal per bpm (assuming you fit within the general population) on your polar so that your kCal count will increase at a set rate for a given heart rate.

Next, once you have set your OwnIndex value and your kCal count should be more accurate (not sure what the % is..), you can then sit on the iMagic at say a 75% HR value and then note the kCal and wattage on the iMagic vs the polar.

Once you have the kCal on your iMagic and your polar, divide one by the other (and multiply by 100) and that is then the scale factor to set in your iMagic.

Accuracy wise I'm not sure how well this would work as it relies on the OwnIndex formulation accuracy and assuming your kCal per bpm fits with this through your HR range. What I do know is that it's more accurate than the default scale factor the iMagic has.

What I found, for me, was that I needed to adjust the iMagic back around 15% (scale factor 115), which in one sense was a bit disappointing, however it was the final landing back on planet earth realising that I was not ready to enter the tour. Plus, my sprint power decreased back below the 1000W level, which is a good target for me now.