Why you need an HRM -with pics

SuperSexyDork · November 2012

Good thing I like spankings as I suppose I'm about to be spanked by a moderator! :laugh:

Azdak · November 2012

He is not starting a fight just for the sake of it--he is pointing out something that is very important in this discussion.

He is asking the question I was going to ask: Since none of you know how HRMs work and how they determine calories and none of you know how machines determine calories, why do you summarily reject one number and accept the other without reservation?

Some pieces of equipment are more accurate than others. A Life Fitness treadmill--if one inputs weight, is walking, and doesn't hold on to the handrails--will usually be more accurate than an HRM. In fact, doing a walking, steady-state workout on a treadmill is a decent way to assess the accuracy of your HRM--if there is a big difference, it usually means your HRM settings are off.

Many people don't realize that unless your HRM is set up with your ACTUAL maximum heart rate and a close estimate of your maximum aerobic capacity, even quality HRMs like Polar can have a significant error.

I explain this in more detail here:

http://www.myfitnesspal.com/blog/Azdak/view/exercise-calories-sometimes-the-cardio-machines-are-more-accurate-404739

jonkers2012 · November 2012

thanks for taking the trouble to post this info. I always suspected a difference, but not such a wide difference!

Azdak · November 2012

I'm stealing that. Just letting you know.

MassiveDelta · November 2012

For me this is completely the opposite Every machine Underestimates my caloric burn rate. But its only by 20-50 cals per workout.

FullOfWin · November 2012

Please take your logic elsewhere. There is no place for it around here.

On another note, I lost 45lbs getting all the way down to 12% bf without tracking calories burned by any activity. I think my algorithm may be more accurate. Do same exercise every week. Eat same calories every day. Adjust calories based on results.

_JR_ · November 2012

My issue with this statement is that you referred to "some" pieces of equipment being more accurate than a HRM that isn't set up properly. "Some" is a pretty vague statement.

1. I've never seen a piece of equipment that states it is one of the more accurate ones. How does anyone know which one is right and wrong.

2. Not dialing in your HRM would fall under "user error". When someone like me takes the time to dial it in properly, does your statement still stand?

The bottom line is if you are losing weight with the numbers you record, it doesn't really matter in the end.

Heather1899 · November 2012

I've always wanted a HRM...I'm jealous!!
But I have lost all of my weight without a HRM! I have never done machines at the gym that tell me calories burned, I always do dvds at home. I just input those into whatever website I am using. I guess it must have been accurate enough, I've lost over 100 pounds...
Then, last year I went and bought myself a HRM! I don't know why, but it just didn't work. I could get it to come on and give me numbers but they weren't consistent. Like it would give me a high number, then a low number for my heart rate...and all in a short time it seemed it just wasn't working to keep my heart rate?
Decided it was flawed and returned it. I didn't buy a replacement, figured I've made it this long without one...

DavPul · November 2012

TRADEMARKED

DavPul · November 2012

Stop that crazy talk! Everyone knows the only way to lose weight is to workout more then eat it back so that you net zero! Lowering BF % can only be accomplished by discovering more perfect calorie counting methods/devices.

Perhaps your mind was subliminally counting calories for you?

FullOfWin · November 2012

I counted what I ate, just not what I burned

Yogi_Carl · November 2012

I didn't read this as fighting talk. I think it is a legitimate question - how do you know it is the machine that is out and not the HRM? If this were a science project you would need to present evidence to satisfy this.

Having said that, I do find that MFP must overestimate calorie burns per exercise because when I was first here I used to log my exercises from MFP and eat all my calories back and I either stayed the same weight or put weight on!

What I have done now is not eat my exercise calories back at all but I have increased my default settings from Sedentary to Light and just make sure I train every day in some way for at least 30-60 minutes. That way, on arevage I am training regularly on a steady deficit and I don't have to sweat about how many calories a particular activity demands.

Just my humble offering.

tommygirl15 · November 2012

Thank you so much for posting this! I'm so glad I got a HRM!

californiagirl2012 · November 2012

I totally agree. I don't trust any of the numbers. I use a basic HRM just to see what my HR is for various exercises. When it comes to calorie burn I ignore it. If I need to eat a few more calories in the evening because I worked out hard (now that I am in maintenance and not needing to lose) then I simply eat a bit more. It worked well for me to ignore the "exercise calories" completely when I needed to lose weight, and it works well for me in maintenance for over a year now to just listen to what my body needs. It's really not that complicated. If you are gaining weight due to eating exercise calories then back off some calories, if you have low body fat and need more energy eat a bit more.

_danjo_ · November 2012

I had the same experience the other day on an elliptical. I entered my age and weight and after 28 minutes the machine said I burned around 425 cals, but my HRM said 294. Interestingly, MFPs calculation based on time was close to my HRM (but I use my number). I was surprised how wrong the machine was.

3foldchord · November 2012

Dauntless, quick question.... Do you know if your normal heart rate is higher or lower than 'average'... Mine is high, and I often wonder if that changes my calorie burn..... I keep debating getting a HRM

chroniclesofthinoholic · November 2012

Ever since I started using the HRM I found out I''ve been burning way more than what mfp calculates for me...I've never reached a 300+ calorie burn in an hour with mfp logging in but with my HRM it shows around a 500 for my one hour of workouts!....l'm glad that it worked the opposite way for me :drinker:

Chris_2013 · November 2012

To the OP, I totally agree with your findings. My workout summary on my Precor elliptical wearing a heart rate monitor always comes in 25% lower in calorie burn than what MFP suggests I burned. I'll trust the heart rate monitor every time.

Yogi_Carl · November 2012

I don't know because I haven't got one yet (one on the way in post) but:

Is it possible to calibrate your HRM to your resting heart rate for a minute to make sure it is accurate there and then expect the HRM to read accurately as your own HR increases?

That way you would know your own HRM is accurate and comparable to the machine readings.

coolraul07 · November 2012

Some treadmills (like the ones I use at work) factor in your weight AND your heart rate to determine calories burned. I noticed that during a weight loss plateau during the summer, I would do the exact same workout but the calorie burn would decrease over time. I realized that as I got used to the workout, my HR would decrease over time and that would be reflected in the calorie burn. I don't think that the OP's pictures prove definitively that the HR is more accurate... or less accurate. However, it's ALL estimates anyway. Someone that matches my age, height, and weight doing the exact same workout could easily have a dramatically different burn based on numerous factors (body fat %, heart rate, etc.)

Personally, I compensate as follows: set MFP to sedentary (true), record my cardio, and eat back NO MORE THAN 50% of the burned calories. It's worked for me. :happy:

kristy6ward · November 2012

Ive done my own tests with the gym machines vs. my hrm and found that the difference between the two increased the longer the exercise went. But my problem with the whole calorie calculation thing is I believe I might have a higher max heart rate than 'normal' and that skews my readings. I don't even feel like I'm working unless my rate is higher than 157.

heybales · November 2012

So what makes everyone think that because the HRM is lower, it is therefore more accurate?

Strange concept. These two things are different, therefore one is correct, enie menie minie moe - awww, just pick the lower one, because I thoroughly understand how HRM works.

Just so ones can understand what is happening, for walking and running up to 6.3 mph level - your treadmill is more accurate by a huge margin over your HRM, even if it has correct stats in it.

http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

Take a look at the study results in the 2nd post - you'll never get a HRM that close to accurate. Because of every reason in the 1st post.

heybales · November 2012

Excellent point, if you have the HRM with default HRmax stat, you calorie burn estimates are way off.

heybales · November 2012

Actually, 2 people that weigh the same, regardless of gender, age, bodyfat, ect, will expend the same amount of energy to move the same mass at the same pace. Barring one running with a club foot or such, or running strange.

The difference in HR merely reflects how in shape someone is in expending that energy. If high, not so much, and mainly carbs burned. If low, more fit, and mainly fat burned.

Just like the exercycles that use a electric motor to provide resistance. That is so many watts, watts is energy, to overcome it, you expended it. Simple as that.

As you get more fit, unless your watch has a VO2max stat, you are actually getting under-estimated calorie burns.
Because your heart is beating slower to provide the required oxygen because you are more cardiovascularly fit.

Azdak · November 2012

This is a general discussion--I was taking issue with the fact that you and others were making blanket statements about the accuracy of HRMs vs machines that were patently false. And you were attacking without cause or proof someone who was properly questioning the OPs original premise. And, as support for my "some" statement, I specifically identified one of the pieces and described how it was more accurate.

1. I'm not sure if you read it, but I go into a lot more detail in the blog, identifying specific groupings of machines that tend to be more accurate than others. Not every equipment manufacturer (nor HRM manufacturer) publishes their data, so there is no way to state with certainly exactly how they derive their numbers. So, in answer to your question, there is no way for the average person to know. (But there is also no way to know how the HRMs derive THEIR information, which is why the "HRMs are always most accurate" statement is so misguided). That's why I take the time to share my experiences on the forums -- to help point people in the right direction so that they do not make big mistakes, and to correct the large amount of misinformation on the subject.

2. Depending on the exercise modality, yes, the statement still stands. It is much more accurate to measure ACTUAL workload and use it to estimate calories than it is to INFER calories burned based on a mathematical "fit" of an indirect effect (i.g. heart rate) of a physiological process (oxygen uptake) to the average workloads of an experimental sample. And it hasn't been mentioned, but there is also the issue of "cardiovascular drift". During longer workouts (for me >30 min), heart rate will start to increase without any increase in workload (or oxygen uptake). For me, if I start running on a treadmill @ 6 mph, my heart rate for the first 5 min might average 115, but by the end of 45 min, I'll be pushing 140. With no change in workload. My VO2 (and thus calories burned) hasn't changed, but my heart rate has. Sometimes there is a 30% increase in my HRM calories burned over a 45 min workout comparing the first half to the second half with no increase in workload. In the real world, that should not happen, but it does. So, yes, there are always inherent weaknesses in HRM calorie estimations, even under the most "ideal" conditions. However with some machines (particularly elliptical cross trainers), the calorie counts are so off, HRMs, even with all of their weaknesses can be more accurate--as long as they are quality models (higher-end Polars, Suunto, Garmin) and they are set up properly.

As for your last statement, that's a different topic. I am only addressing the assertions of the OP, and your follow up questions.

pinkraynedropjacki · November 2012

Actually I've found if you put your own exercises in with your HRM rate (mine is HRM-RUN) and then MFP comes up with the same number based on what I set it at way back at the start, it seems to follow my HRM rate perfectly. But if I used MFP's set running workout it would be way way out. SO now I only ever use my own rates.

Azdak · November 2012

I would be curious to know what brand of treadmills you are referring to. In most commercial exercise equipment, the HR display is separate whatever part of the console board estimates calories. There is a modular Polar receiver that plugs into the console and that picks up the signals from your chest transmitter. In the absence of a chest strap, the sensors on the handrail are used to sense heart rate. If the machine has heart rate interactive programs, then the heart rate signal will be used to adjust workload.

I don't know of any commercial treadmill that uses heart rate as part of the calorie estimations. However, I have been out of the front lines of the equipment business for 3 years, so someone might have come up with a new feature, and, if so, I would definitely like to investigate.

Littlegurl · November 2012

I have a Polar FT4 too. However, I have a high metabolism and mitral valve prolapse. MFP and exercise machines UNDERestimate my calories burned every time. It's just individual. And a HRM is really the most accurate.

lwagnitz · November 2012

I just always log 10-15lbs UNDER my actual weight when I use the machines, and then usually take off calories when I log in MFP to play it safe.

Azdak · November 2012

<sigh>

Why you need an HRM -with pics

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