When do you use your HRM?

[joestencowwife]

I just got my first HRM and my intent was to use it to more accurately calculate my calories burned and to assist in reach my goal rates while exercising. I had thought to wear it pretty much all day, since I tend to do small things during the day to keep my heart rate up as well as my dedicated work out times. However, I keep seeing references to wearing it while exercising but nothing on just regular daily wear...

Thoughts?

[Colinm39]

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@joestencowwife wrote:

I just got my first HRM and my intent was to use it to more accurately calculate my calories burned and to assist in reach my goal rates while exercising. I had thought to wear it pretty much all day, since I tend to do small things during the day to keep my heart rate up as well as my dedicated work out times. However, I keep seeing references to wearing it while exercising but nothing on just regular daily wear...

Thoughts?

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@joestencowwifeI have read on these forums that using a HRM for day to day use is probably only helpful to record your heart rate and for a measure of calories to be effective I believe your heart has to be over a typical figure of say 80 bpm or over 50% of your maxHR.

This link has some simple explanations and @slysam may chime in because I'm sure I read her comments in the older Forums.

For me, I only use the HRM's for planned exercise and as I'm typing now my HR is 37% of maxHR and of no use for my calories. But when I'm walking and I get my HR up around 65-70% the end result calories are within a few calories of the Fitbit One's calorie calculation. That is walking on flat areas, but as soon as I get my HR up to 75-80% walking up pavement gradients the HRM has a calorie burn about 20% higher than the Fitbit because Fitbit cannot measure that exertion.

Of course wearing it all day will depend on whether you have the wrist sensor type or the chest band type.

Please keep us posted.

[Heybales]

As Colin indicated.

The formula for estimating calorie burn to HR is ONLY valid for exercise, and only steady-state aerobic exercise at that. So same HR for 2-4 min at a time, and aerobic.

So it can be useful during anaerobic non-steady-state exercise still, like lifting, or intervals, or many exercise classes where the HR is jumping all over the place, just as indication if the HR is getting as high as it normally does.

Because not only are your muscles getting a workout, so is your heart/lung muscles and cardio system, it improves faster sometimes.

So you'll be doing a workout at about the same weight, moving just as intense as normal, and therefore burning the same number of calories, but you'll find the HR is lower after a while - meaning you are becoming more fit.

Unless you increase intensity. So you may have had the strength to push hard enough to shoot the HR up to X, but you've been tired lately and eating too little and exercising too much, and now doing the exact same workout, you can only push the HR up to say X-15.

That would be for an exercise class.

If that was weight on a bar, the same result would be you couldn't lift as heavy, you took weight off.

Or treadmill, you slowed it down.

So it can be useful even on exercise the calorie burn is inflated for.

And yes, all day wear isn't in exercise zone, so that's usually inflated too.

[Colinm39]

@joestencowwifeAn example of inaccuracy with the HRM and this example really suggests that you have to be conscious of the RPE (Rate of Exertion).

Last summer it was very hot and fortunately I had a 6 monthly checkup the same day. It was 105oF (41oC) outside and I was inside and no humidity. I had been doing some early morning light gardening and I happen to have left my HRM on (Polar rs300x).

So sitting watching the midday news and my heart was beating on average 96 bpm, unusual for me because around 100 bpm is my walking speed on the flat. When I got to the doctors, it was still 96 bpm he found nothing abnormal and his reaction was people at my age have a range of 60-100 bpm. I don't feel I was lacking hydration because my bodily fluids were on the low scale of yellow. Maybe it was just my body keeping cool.

Therefore in that context the calories were inaccurate, the calorie burn had me walking at about 3.5 mph (5.6 kmh) and I was sitting and relaxing...

When I started using a HRM many years ago I was interested in the Recovery Heart Rate (RHR) and as I have aged it is quite interesting the graphs gradients of RHR have kept the same even though my maxHR has dropped through the years. My resting HR is 60 in this graph but again as I'm typing now it is 57 bpm and can get down to 42 bpm when I'm asleep. Just my genetics... Here is another link

[Ladyvalk]

I like to wear mine when I am walking, jogging, riding my  bike  or taking a class

[WendyB]

It is not meant to be worn all day. Only with real exercise. Listen to the others.

[Heybales]

Ok Colin, someone that likes tracking data as much as me it appears! 

My Garmin only shows the HRR for 2 min time span, on pop-up window, but not saved with data.

Had previous HRM that let you select 1 or 2 min time span, and it saved with the data, but couldn't upload any of the data, so had to record it elsewhere, and I usually didn't.

I still don't record it, because usually a jog ends with 5 min walk, so the drop is minor, or the bike I stop the workout and slowly come in stretching and such, so another unfair view.

It is interesting view of fitness level though, even better than resting HR in some ways.

Oh yeah, elevated for cooling is exactly a reason. If actually in the workout and still hot and dehydrated, then elevated for thicker blood and cooling reasons.

Now, and this speaks to this subject well too - have you even done and recorded your HR during say a vigorous 1 hr walk with treadmill kept at exact same speed and incline - so no actual change in effort or intensity. After initial warm-up spike dropping HR back down, most will show a gladual increase of HR through the whole time. Cardiac drift. Sometimes associated with thicker blood, sometimes just happens.

It's interesting to see how much change you get.

Equaling interesting is another test starting at same effort, but during the 60 min changing speed and/or incline so HR does change up and down, but by last 10 min coming back to same effort as at start, and is HR still elevated the same amount?

[Colinm39]

@Heybales I will get my trusty Polar Rs300x out and check the results. The image is me 55 years ago, 75 in a couple of days so no treadmill walking but fairly consistent walk speed. I'm currently looking at my VAM because I earned 46 minutes out of 48 minutes which was a total.surprise. 

[slysam]

I mainly wear mine for exercise, sometimes I will do something right after a workout and continue to wear it. I personally don't feel they are comfortable for all day use and also the calorie burn estimate is not accurate for non aerobic exercise. Saying that, if you are wanting to use it to see what your heart rate is during various activities--that is fine. I think that would get old fast, but can be nice for improving your self awareness. I am sure someone mentioned this, but the reason the calorie burn estimate only applies to aerobic exercise... Calorie burn is not actually measured by heart rate. In a lab they base the measurement (or estimate?) on oxygen use. One reason that your heart may speed up is to supply more oxygen to working muscles (especially during aerobic exercise) but there are other reasons that may not have much to do with calorie burn. Heart rate monitor companies have done their own research to correlate exercise heart rate with oxygen use, they are usually actually estimating your oxygen use from your heart rate and estimating your calorie burn from your estimated oxygen use. This is an estimate not a direct measure and it involves assumptions about your metabolism, fitness level, etc based on your profile stats and average heart rate during the workout. Fitbit did something similar when developing their product with walking and maybe running? (There is a very good post about this process on the fitbit blog from a few years ago). You know, I can't really say that you are not burning more calories if you are sitting but very nervous (i.e. waiting for an interview). Maybe you are burning more as it seems the metabolism is reved during fight or flight mode--but this situation does not apply to the formulas heart rate monitor manufacturers base their calorie burn estimates on and likely any bonus burn is tiny. Using overly generous calorie burn estimates can hurt your results.