Recommendations on the best way to track calories spent in exercise?

burnsjulia

The calories allotted in the database here seem a bit random - surely we must each burn calories at different rates given different fitness levels and body sizes? Plus there's no differentiation on effort here -- I interval train regularly and there are days when I slack off and go slower and must burn less.

Does anyone have a (not very expensive) recommendation on a tool to track calories consumed? "Steps taken" doesn't seem like a good measure for me.

Another question too: why does the database here give no calorie credit for strength training? I'm starved on days when I lift extra.

Thanks!

bwogilvie

The MFP calorie database does use your most recent weight check-in to calculate calories burned. However, it overestimates the calorie expenditure of many activities; it's not too far off for running, which has been extensively studied, but for other activities it can be laughable. Weight doesn't matter very much for cycling on flat ground, for instance; over 12 mph, it's air resistance that is the most important factor.

For estimating calories consumed in moderate to intense aerobic exercise at a fairly constant intensity (such as running 45 minutes at about the same pace), you can use a heart rate monitor. Even its results will be only an estimate; it measures heart rate and then uses a formula, sometimes a proprietary one (as with Firstbeat, Inc., whose algorithm is used by some Garmin and Suunto HRMs), to estimate calories burned. That, in turn, implies a relationship between heart rate and calorie expenditure, but over 20% of the variance in people's calorie expenditure in one study was not accounted for by heart rate.

As you get fitter, for example, your heart rate will get lower when you exercise at the same intensity (and burn the same number of calories), because your left ventricle will enlarge and pump more oxygenated blood with each heartbeat. Cycling on a flat road at 17 mph used to get my heart rate up over 170; now it usually hovers around 145 at that speed depending on wind. I'm burning the same number of calories, but a low-end HRM would think I was burning fewer. (Ironically, most HRMs overestimate calorie burns for unfit people, and underestimate them for fit people.) My bike HRM, a Garmin Edge 800 cycle computer, allows me to enter my fitness level, which the algorithm includes; its estimates seem fairly accurate (they agree with my actual measured weight loss).

HRMs with features like that, though, tend to be fairly expensive. If you want something better than MFP's database but cheaper than a high-end HRM/GPS watch, you could get a cheaper HRM, see what it estimates, then compare your actual loss over the course of a month with your HRM's estimates. If you're logging your calories eaten accurately (a big if; most of us miss a couple hundred calories a day), any discrepancy will involve your exercise calories burned.

Or, finally, you could do what many MFP users do: take MFP's estimates, log 50-75% of them to account for its inflation, and then change the percentage after a month or so when you figure out how accurate it really is.

47Jacqueline

"As you get fitter, for example, your heart rate will get lower when you exercise at the same intensity (and burn the same number of calories), because your left ventricle will enlarge and pump more oxygenated blood with each heartbeat. Cycling on a flat road at 17 mph used to get my heart rate up over 170; now it usually hovers around 145 at that speed depending on wind. "

This ^

I use an HRM because both the activity trackers and MFP are not attuned to my weight/height/age to record my burn.

My experience with Zumba, for example, is MFP says I burn over 500 calories in an hour, and my HRM maybe gets me to 400.

brianpperkins

47Jacqueline wrote: »

"As you get fitter, for example, your heart rate will get lower when you exercise at the same intensity (and burn the same number of calories), because your left ventricle will enlarge and pump more oxygenated blood with each heartbeat. Cycling on a flat road at 17 mph used to get my heart rate up over 170; now it usually hovers around 145 at that speed depending on wind. "

This ^

I use an HRM because both the activity trackers and MFP are not attuned to my weight/height/age to record my burn.

My experience with Zumba, for example, is MFP says I burn over 500 calories in an hour, and my HRM maybe gets me to 400.

And they're both probably wrong since HRMs are not designed or programmed for dance.

burnsjulia

Thanks for the responses. I was looking for the easy answer - which is rarely to be found. I found this comparison of fitness trackers on Wired from 2012 and it seems like a good comparison. http://www.wired.com/2012/08/fitness-trackers/

From the article, it looks like running may have some decent estimates to it, but a torn adductor is keeping me off the roads for several more months. Plus most of and my preferred my work out (even when I could run) is martial arts and interval training.

My husband was given a Nike Fuelband which he hasn't used so I'm going to give that a shot given that we have it on hand. Sounds like tracking calories spent in exercise may be more of an art than a science.