HRM accuracy ~ Running intervals when unfit

TourThePast

My Polar FT4 seems pretty accurate with calories, but I'm curious about one issue.

I'm running intervals, but as I'm not very fit yet, my heart rate takes a relatively long time to reduce, even when I'm walking in between.

However, all the HRM can calculate on is my heart rate, so it's presumably assuming I'm still working hard, when in fact I'm walking. Does anyone know whether, for interval training, I should be taking something off the calories shown as burned, and if so by how much?

almondbliss

Bump....Curious about this also.

jmijaressf

With the Polar HRMs, the calories calculations are based on height, weight, fitness level (METS), and your heart rate during the workout. If you're heart rate takes a while to come down during the recovery phase of your run then the monitor is using the current heart rate to calculate calories.

I wouldn't take any calories off when you're doing intervals. The calorie count with the Polar HRMs, regardless of how your working out, will still be fairly close.

jmijaressf

You'll also find that as you get more physically fit, your heart rate will recover faster after a hard interval.

BigBoneSista

I agree with jmijaressf. Whether you are walking in the recovery or hitting it hard your body is still actively burning calories so you are fine. As you progress with your workout regimen over the next months you will definitely begin to see a difference in your heart rate and how many calories you are burning currently and with how many you will be burning then.

NikkiDerrig386

Maybe you are not walking slow enough and thats why your HR isnot going down much. Why would you take calories off? If your HR is up your burning calories it doesnt matter what you are doing, If you were lying there and your HR was 189 then you HR is 189 and your burning calories.

TourThePast

I wouldn't take any calories off when you're doing intervals. The calorie count with the Polar HRMs, regardless of how your working out, will still be fairly close.

Thanks, I appreciate the advice.

As you progress with your workout regimen over the next months you will definitely begin to see a difference in your heart rate and how many calories you are burning currently and with how many you will be burning then.

Yes, I was embarrassingly unfit to start with, walking at 4.5kph on the treadmill was more than enough to get my heart rate up to 130. Then I had to raise the gradient - and then again... When walking at 4.5kph at 12% wasn't enough to raise my heart rate high enough, I tried running for 20 steps every so often.. Which is how I came to think that maybe C25K might even be doable for me.

If you were lying there and your HR was 189 then you HR is 189 and your burning calories.

Ah, but not 189bpm worth of calories though, this is why I asked. In your scenario, the only major work being done if I was lying down is by the heart, which is minimal compared to what I'd have been doing to get me up to 189bpm. Remember the heart is only indicative of what the body is doing, not a direct burner of calories. For instance, if I was a passenger in a car which nearly had an accident, my heart rate might go up very high, but I would not be burning a lot of calories.