Should I deduct calories off of what my HRM says I burned?

numinousnymph

I have a Polar FT4, it comes with a chest strap (which I've been told is more reliable than ones that just measure HR from your wrist), but isn't a more advanced model where I can put in my VO2max, things like that that make it more personalized. I just put in my age, gender, and weight. I've heard that HRMs are less reliable for women, and less reliable for exercises such as HIIT that are not steady state. I've read that some people deduct a certain percentage of calories from what the HRM shows they burned. I think that my HRM gives me a reasonably accurate picture of what I've burned, especially since it shows half as much burned as ellipticals, which I know are notorious for grossly over-estimating calories burned. With treadmills I've noticed it's almost exactly on par with the calorie burn showed on the machine. I usually split my workouts so half or a bit more than half is steady-state and the rest is HIIT. But, just to be safe, when I enter my exercise calories in MFP I've started deducting around 15 - 20% of what my HRM says I've burned. Do you think this is a good idea? Should I deduct more? Less? Nothing at all? Any input would be appreciated

_Waffle_

They're meant to be used with steady state cardio type exercises. I haven't heard that they're less reliable for women. At any rate they're still a rough estimate of the calories you burn so it's not exact. It's like the car company saying you get 23 MPG. That's not factoring in wind, heat, tires, etc.

The important thing is to be consistent. If you want to deduct 15% off of what it says then stick with that and see what the results are. You should know within a week or two if you're under or over compensating based upon weight gain or loss. Adjust as necessary.