Could someone explain HRM please?

DrJanet98

I've seen a lot of references to using a heart rate monitor to determine calories burned. Many seem to feel it's one of the most accurate measures of calories burned. But your heart rate can go up or down for a lot of reasons! Do you burn more calories if you've had a cappuccino than if you don't? Do you burn calories riding a roller coaster? (Okay, that's an extreme case, but you could be upset or happy versus bored while on the treadmill.) I'm just a little curious about how it's supposed to work. Can anyone explain the physiology for me? Thanks!

Lina4Lina

I did a little googling and found this website, there is a link to a study but there is also a synopsis on the site. It is meant only to be used during exercise. And it is just an estimate, better than most estimates.
http://www.braydenwm.com/calburn.htm

neverstray

Lol. U just pointed out the problems with it. It's not all that and a bag of chips. It's just a basic estimate of your heart rate during exercise. But, it's not really that accurate. It's good enough for most people who do cardio exercise. It's not good for any other reason.

skierxjes

It gives you, yes, an estimate, based on height, weight, age, gender and heart rate. It's the best estimate of all.

kuger4119

Agree that there are factors beyond effort that affect heart rate. They are still very good at helping you estimate heart rate. One thing to note is that newer monitors estimate calories differently than older ones. I have a Mio watch that does a good job of estimating heart rate compared to my new Garmin GPS watch with an HRM strap but the new watch projects noticeably lower calorie estimates than the old watch did.

The Mio appears to be prone to overestimating calories burned while I am lifting.

fionat29

If you use it to measure your calorie burn during actual exercise then it's a great way to measure that burn. It can give you a decent idea of how many calories you've burned during each exercise session.

JamesBurkes

The manufacturers test lots and lots of people of different weights etc exercising (usually steady cardio such as riding a bike or running) at different intensities/heart rates. From these tests and measurements, they can then create algorithms to estimate how much someone of a certain weight, exercising at a certain heart rate, will burn. So yes, when you tap in your weight and then it measures your heart rate, the calorie number it pumps out is an estimate but it is generally a pretty accurate one.

A few caveats, however.

As I say, HRMs don't actually measure your calorie burn - they just use your heart rate as a GUIDE to calculate how much you're probably burning (based on their testing of people of a similar weight). However, as the calculations are based on all their measurements of people cycling/running, the accuracy of HRMs diminishes for other activities.

This is why they're generally not much good for calculating calorie burn from lifting weights.

Also, if your heart rate rises for other reasons (being anxious, being hot, being full of caffeine) then obviously they are completely inaccurate, as the HRM thinks "Wow, this person is running really hard! Their heart rate is maxed out!" - they must be burning a ton of calories!" Whereas in reality, if you're sitting in a roller coaster, your heart rate may be high but you're only burning the calories you would usually burn sitting down - after all, you may be in a roller coaster, but all you're actually doing is sitting - you're not using your muscles to burn up calories!

So they can be very useful for uninterrupted bouts of cardio exercise. But be wary of using them for other things (at least in terms of working out calories burn). It is however, often useful to know what your heart rate is at different times, and they tend to do this very well, regardless of activity).