Calories burned discrepancy

LoLoGB

So MFP puts my 30 min strength training at 98 calories and my 20 min cardio at 90 calories. But my Polar FT7 which uses heart rate monitoring has me at 321 calories total for the two. That's a large difference. I would think Polar is right bc configured to my age, height, weight and constant HR monitoring during exercise (and the SL 5x5 will get that heart rate UP!)

What are your thoughts?

myfatass78

So then use the Polar measurement. MFP is best guessing.

heybales

HRM formula for estimating calorie burn is ONLY valid for steady-state aerobic exercise, same HR for 2-4 minutes.

The correlation between HR and calorie burn is totally about heart beating enough to supply required oxygen for your level of effort, that calculated amount gives the calories burned for the effort.

Lifting if done right is both anaerobic and opposite of steady-state - totally invalid use of HRM for calorie burn.
It should inflate a lot.

When you get done with a lift, say squats, and you notice how high the HR is, how long does it take to lower to the normal HR that is needed for just standing there looking at numbers?
That whole time it's lowering, if it even reaches standing resting HR, is inflated, receiving a higher calorie burn than standing there actually requires.
And even the spike wasn't aerobic anyway, as if doing squats you better have been holding your breath, so no new oxygen required for the actual effort. Body obviously needs it between reps.


That level of HRM is attempting to do the above math for proper use by assuming some stats for you.
HRmax is 220-age, though you can adjust that if you have a better handle on what it actually is.
VO2max is assumed to be good for you (gender/age) if your BMI (height/weight) is good.
If BMI is bad, it assumes bad fitness level and lower VO2max.
If bad BMI but you are fit - bad estimates, usually under-estimated.
If good BMI but out of shape - bad estimates, usually inflated calorie burn.

Suggest you test it out for the valid cardio uses. At least following this method you don't need to log it, and can just use it for it's intended purpose - monitoring HR for improving cardio workouts.

http://community.myfitnesspal.com/en/discussion/774337/how-to-test-hrm-for-how-accurate-calorie-burn-is

Because even the nicer ones with self-tests and those stats to change can be very wrong, even using lab measured stats.

http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study

MFP calorie burn for Strength training is actually based on studies, and is actually a good estimate.
It is indeed low, compared to equal time for cardio. And that is correct.
It's for sets and rests of 2-4 min and reps 5-15.

And the cardio depends on what it was.
If running or walking, the database entry is likely more accurate if you did that exact speed indicated for the whole time given.
If cardio has no intensity level to it - who knows what the study was based on.
Actually, it can be looked up.