How accurate are heart rate monitors?

ljmcf

Hi All!

I've been using my Polar FT4 watch while exercising and I was wondering how accurate it is? I burn what I would expect to burn in Body Pump for example, but sometimes I go for a walk round the local loch (takes about an hour or so to get round it) and it tells me I burn 600-odd calories which I wouldn't really expect? I'm not walking particularly fast!

Thoughts would be appreciated

IsaackGMOON

A lot more accurate than machines or MFP.

I can't really give you any figures, but trust me, they are a lot more accurate in comparison.

ScubaSteve1962

Why you trying to start and argument (LOL) But seriously, was your heart rate elevated during the walk? Some are more accurate than others, because you can put more information in them.

I use a Polar V800, I'm able to do the fitness text and orthostatic test, while some say it may not be accurate, I don't get outrageous calorie burns, so I go by it. During a 30 min 3 mph walk at an inline between 4 and 7, with an average heart rate of 121 bpm, I burned 227 calories.

MeanderingMammal

ljmcf wrote: »

I've been using my Polar FT4 watch while exercising and I was wondering how accurate it is?

Accurate for what. As far as HR monitoring is concerned, it's pretty accurate, at least enough for casual use.

I burn what I would expect to burn in Body Pump for example, but sometimes I go for a walk round the local loch (takes about an hour or so to get round it) and it tells me I burn 600-odd calories which I wouldn't really expect? I'm not walking particularly fast!

The reliability of HR monitoring to indicate calorie expenditure only applies in a limited range of circumstances. The research used as the basis for the algorithms was carried out on treadmills, cycle and rowing ergometers. Where HR is lower then the ability to differentiate between base consumption and exercise consumption is very limited, beyond the lactate threshold then the channels for energy consumption change and the relationship breaks down. If HR fluctuates significantly during exercise then the relationship with calorie expenditure breaks down.

So if you're running, cycling, rowing, swimming etc in your aerobic range, 50%max HR to about 80% then they can be a reasonably good indicator of calorie expenditure. If you're not then you're liable to error.

If you're walking, and your HR is in the range where it's meaningful, from a calorie consumption perspective, then I'd suggest a trip to the GP.

In terms of baselining, I'm 160lbs and would anticipate about 100cals per mile running, and about 50 cals per mile walking.

My device is a GPS system, so only uses HR to corroborate the calorie estimation. So if I go on a steady paced run then it's reasonably accurate, if I do sprint intervals then I'd deduct about 50% from the total as a more realistic assessment. Similarly if I'm trail running.

I'd add that the meaningfulness of the assessment reduces if the training goes on for more than about an hour, because HR drifts upwards over the course of a session.

brianpperkins

HRMs are neither designed nor programmed for anything outside of steady state cardio performed at least at a moderate level. They do not accurately estimate calories from things like Body Pump, weight lifting, yoga, or low intensity activities such as walking .... they overestimate for those activities.

I see the same desire to believe the claims of HRM makers that I see in the desire to believe the claims of fad diet plans. The outcome is the same ... disappointment. Either disappointment because the fad diet didn't deliver as promised or because the calorie burns from the HRM were inflated and even using half of that number was an exaggeration (such as your 600 calorie mall walk).

professionalHobbyist

Wear it to get your blood pressure checked.

I have compared mine to 3 different cuffs. Two at Dr offices and one at the Walgreens Pharmacy.

They were always very close to each other.

Calorie burn calculations are where some say it gets fuzzy.

Supposedly those HRM watches struggle with intervals or HIIT for calorie burn algorithms.

So I just go by heart rate targets and ignore calories.

If you set a goal of 93% of your max heart rate for a 30 second sprint, who cares about the calories! That is a great cardio goal. Second interval 96% or HRM max.

I think a HRM is an awesome tool for health management. Use it for what it is best at.

If you get a chance, wear one in a sauna. Do just a little work like sit ups or squats. It is interesting the effect of the heat on body stress. Take it easy of course. But being tired and hot, doing deep knee bends raises your heart rate up.

I don't know the science behind it but it is easy to see.

No steam room though. Electronics and steam... Not so much.

I use an old Polar FT40 with chest strap.

I will be getting a new device with GPS since I am getting more into bike riding.

Always new gadgets out there and next year something be the next essential thing...

Ha! Marketing...

Tedebearduff

IsaackGMOON wrote: »

A lot more accurate than machines or MFP.

I can't really give you any figures, but trust me, they are a lot more accurate in comparison.

What they are is the "best guesstimate"..... They are actually all an assumption.... should just go with the free option IMO which would be MFP or machines. The site already considers your activitly level when you enter it ...

coryrood

I've been logging every calorie my m400 has given me for everything from walking to cycling to weight lifting. I've been eating back 100% of them and I've been maintaining. Trying to actually gain lean mass. It's all trial and error. Pick a method stick with it for a few weeks and make small adjustments as needed.