Exercise estimates WILDLY out!

JustinJoanknecht

Hey all

This topic continues to confuse me.

I've noticed for some time now that the exercise estimates on calories burn that Runkeeper and MFP make for my activities are too high - and when I compare them against my Heart Rate Monitor (Polar FT7, all correctly calibrated for my age, weight etc) they are too high - but how much higher depends on what I'm doing???

Eg when I play squash for 45mins, RK estimates it at 952 calories - yet my HRM measures it at more like 600-700 on average, so sometimes over 50% more!

when I run for 2.5 miles, RK measures the distance and time etc and generally overestimates the cals burn by about 16-20% compared to the HRM

but when I walk (a steady 4mph), RK and MFP estimate at about 150-160 cals a mile - whereas my HRM only records it at 40 cals a mile - which is massively out to the tune of nearly 400%! If I go on a nice long 10 mile walk, I could be putting in 1500 calories if I listen to the tools or 400 calories if I trust the HRM - and this massive uncertainty is stressing me out!

Is this possibly because of my atypcial heart rate? (it's very low resting rate...........low 50s if I'm pottering around the house and as low as 42 if lying down and totally still........even a brisk 4mph walk only gets it upto 75 or so)

Can anybody help with this, maybe some experience in the matter?