Basis Peak and BodyMedia Comparison

Yesterday afternoon I played tennis doubles for a couple hours with my team.  I did not do my best - I just wasn't seeing opportunities to get the ball at the net.  But it was good to get back to some tennis.  I also did a comparison in the calorie burns calculated by my BodyMedia device and my Basis Peak.  They were quite different.  The BodyMedia calculated about 560 calories, while the Peak calculated between 350 - 400 cal.  The Peak also counted a lot fewer steps, although I don't have exact numbers.

This morning I did P90X2 Balance + Power.  I concentrated on really keeping my torso straight, which made some of the moves much harder.  My BodyMedia said I burned about 195 calories, while the Peak said about 125 calories; again, a pretty big difference.

I decided to do a test this afternoon.  I walked 500 steps around the house to see what calorie burn and number of steps each device measured.  The BodyMedia counted 469 steps and calculated a burn of 21 calories.  The Basis Peak counted 516 steps and calculated a burn of 34 calories.  This is the opposite pattern compared to what they were doing yesterday in tennis!  So which is correct?  Who knows.  The Basis Peak has definitely been overall counting fewer steps throughout the day and also calculating a lower calorie burn.  I have suspect the BodyMedia calorie burns have been too high for quite awhile, but I thought measuring the steps would be more basic and repeatable.  I guess not.

This afternoon I did my scheduled training run on a treadmill at TCCP, because my treadmill belt is still damaged.  (The repair place is ordering a replacement belt.)  I very carefully noted the start and end on both the BodyMedia and Basis Peak in order to do another comparison.  I ran for 45 minutes, increasing my spead from 5.8 mph to 6.2 mph, averaging 6 mph.  That gave me a distance of 4.5 mi.  This run actually felt pretty good, which I was surprised about, but can't complain.  For the comparison:  the BodyMedia counted 7960 steps and a burn of 460 calories; the Basis Peak counted 7700 steps and a burn of 470 calories.  These measurements were both much more self-consistent that my step test.  Maybe because it was over a longer period of time, so variations average out?  Or maybe running is easier to measure for the devices so they are more reliable?  Who knows.