HRMs and strength training

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  • contingencyplan
    contingencyplan Posts: 3,639 Member
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    HRMs will work for weight training regimens based on compound lifts. They will not work for isolation lifts and will give you an incorrectly high reading.
  • Coltsman4ever
    Coltsman4ever Posts: 602 Member
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    I see. The important thing for me is that I won't have to guess anymore what I'm burning during core class and aerobics class. And if I decide to do c25k outside instead of on the treadmill, I'd need it for that too. I have used MapMyWalk in the past for walks and runs and found it to be very iffy. I also have no clue how much I burn during core class because MFP doesn't have an entry for that, so I just use "sit ups, vigorous". But I have no clue if that's right. And what I burn is an important part of how much I eat. If I'm not eating enough or eating too much that could explain my plateau.

    Very true.
    I cycle every day and MFP's estimate of the calories I burn are double of what my HRM reads.
    I would be very skeptical of any estimates from MFP. They tend to run high in my experience.
  • rose313
    rose313 Posts: 1,146 Member
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    They sure do! Even the number on the machines at the gym seems suspicious to me. I used to use the elliptical all the time...I feel like I could do the laziest workout ever, and not even break a sweat, and the elliptical would say I burned 300 cals in 30 mins. There is just no way. I don't even burn that running.

    I should add that I'm only 5'2 and only slightly overweight, so I don't put up huge calorie burns in the first place.
  • murphy612
    murphy612 Posts: 734 Member
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    I didn't think it would be a big issue but I read it in the manual so just figured I'd check. Thanks for all the info!

    I have the PolarF7, and other people pick up my heart rate sometimes if I'm standing close and they have a polar. Other than than I really like it. I was hesitant about the chest strap too, but you get used to it really quickly.
  • tressatnt
    tressatnt Posts: 77
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    I have a Polar FT4 and use it for my "weight training" at the gym which I have turned into more of a circuit training and ever since I have used the Polar, I finally started dropping some weight. It's helped a lot, love it. If you're doing "weight lifting" the way I do, then it should work for you. I don't lift a heavy set and then walk around reading a magazine like the guys at my gym do. I a set, and move to another right away and keep going and I do 3-4 rounds and I add in some short bursts of cardio like box jumps or burpees or whatever to keep my heart rate up.
  • rose313
    rose313 Posts: 1,146 Member
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    I didn't think it would be a big issue but I read it in the manual so just figured I'd check. Thanks for all the info!

    I have the PolarF7, and other people pick up my heart rate sometimes if I'm standing close and they have a polar. Other than than I really like it. I was hesitant about the chest strap too, but you get used to it really quickly.

    Yeah I'm sure as much as I'm dreading having to wear a chest strap now, I'll be fine with it and probably not even feel it. And it will be totally worth it in the end.
  • heybales
    heybales Posts: 18,842 Member
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    The problem is a technical one. Calorie burning isn't determined by heart rate, it's determined by the number of muscle cells that are activated to perform a given activity. It's the working cells that actually use the energy (calories) and consume oxygen. When working muscle cells need more energy and oxygen, your heart rate goes up to deliver these things to the cells via the blood stream.

    Any muscle that performs a high intensity or maximum effort (strength training) will trigger an increase in heart rate and blood flow. But if only a single muscle group is on the receiving end to utilize that extra oxygen (doing a strength exercise that isolates your biceps, for example), only a relatively small amount of oxygen (and calories) will actually be consumed.

    So while a series of strength training exercises may elevate your heart rate like aerobic exercise does, you're not actually using as much oxygen and burning as many calories as you would be if you were steadily using several large muscles all at once, as when walking, running, swimming, or doing aerobics for example.

    The heart rate monitor doesn’t know whether your increase in heart rate is due to several large muscle groups working (cardio), an isolated muscle group lifting a weight (strength training), or even if adrenaline or excitement is increasing your heart rate. It just knows your heart rate, and the formulas it uses to estimate calories are based on studies of aerobic exercise, not other activities. So, it's going to overestimate your calorie expenditure when the rise in heart rate is stimulated by using isolated muscles at maximum intensity, which is what occurs during strength training.

    In addition to that excellent write up, that change in need during aerobic exercise really takes about 3-5 minutes of steady-state at given level to even out, because the first jump in intensity causes the same spike in HR though not really for the purpose of oxygen delivery.

    So circuit training and classes with weights usually has no steady state for any 3-5 min anywhere in it, so actually still invalid then.

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

    The few HRM's that are valid for lifting and anaerobic sprints really just look at your breathing rate (figured from the fact the HR changes slightly breathing in or out) and decides which one it was. If anaerobic then that HR is just ignored for calorie burn estimate, until HR and breathing return back to aerobic state.
  • marinegirl92
    marinegirl92 Posts: 184 Member
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    Hi there - great thread.

    About a month ago I purchased the F6 Polar HRM - about $70. Best investment I made so far - the chest strap is pretty comfortable under a sports bra. Sometimes I forget I'm wearing it. Yeah - you do have to wet the fabric strips on the chest strap before each use (I dry mine off so I don't get the cold icky feeling) and yeah you do have to wash it once a week. But those are trade offs for more accuracy.

    It's probably one of the more accurate ways to calculate the # calories burned for your workout given that you've programmed that into your transmitter.

    I have found that the calorie burn #'s on gym exercise machines or MFP are bit on the high side. Just last night my treadmill was saying 450 calories burned when my F6 Polar transmitter said 280.

    I did also have a body media device and it just got too complicated with MFP integration (although now you can change your setting to account for this. Plus that dang arm band - hated it! After about 10 days, I just couldn't handle having that armband on my arm. Had to go!

    Good luck! Hope you like your new XXX HRM device!
  • rose313
    rose313 Posts: 1,146 Member
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    I have a Polar FT4 and use it for my "weight training" at the gym which I have turned into more of a circuit training and ever since I have used the Polar, I finally started dropping some weight. It's helped a lot, love it. If you're doing "weight lifting" the way I do, then it should work for you. I don't lift a heavy set and then walk around reading a magazine like the guys at my gym do. I a set, and move to another right away and keep going and I do 3-4 rounds and I add in some short bursts of cardio like box jumps or burpees or whatever to keep my heart rate up.

    That's what I do too! Since I started core class I haven't been doing that as much, though, because the class does the same exercises I did using the Nautilus circuit, except they are much harder because I am using my core strength instead of being guided by a machine. But the Nautilus circuit helped me learn good form so that was really helpful.
  • heybales
    heybales Posts: 18,842 Member
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    I have found that the calorie burn #'s on gym exercise machines or MFP are bit on the high side. Just last night my treadmill was saying 450 calories burned when my F6 Polar transmitter said 280.

    Guess what - that treadmill was likely more accurate by a decent margin than your HRM.

    You've become fit enough the HRM is underestimating your burns likely, or you have the HRmax value set wrong.

    See, many reasons why it's primary purpose of monitoring your HR does NOT translate well into estimating calorie burn, since the 2 have a lose correlation.

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

    Test your HRM again.
  • Mokey41
    Mokey41 Posts: 5,769 Member
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    They sure do! Even the number on the machines at the gym seems suspicious to me. I used to use the elliptical all the time...I feel like I could do the laziest workout ever, and not even break a sweat, and the elliptical would say I burned 300 cals in 30 mins. There is just no way. I don't even burn that running.

    I should add that I'm only 5'2 and only slightly overweight, so I don't put up huge calorie burns in the first place.

    Machines lie, it's their job. You'll be surprised if you run on the treadmill with a HRM how different the calorie burn is compared to what the machine says. If you eat exercise calories it can make a huge difference.
  • BrianSharpe
    BrianSharpe Posts: 9,248 Member
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    Has anyone experienced erratic readings caused by TVs at the gym, cell phones near you, other HRMs near you, etc?

    Make sure whichever one you buy has a coded transmitter.
  • Coltsman4ever
    Coltsman4ever Posts: 602 Member
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    I have found that the calorie burn #'s on gym exercise machines or MFP are bit on the high side. Just last night my treadmill was saying 450 calories burned when my F6 Polar transmitter said 280.

    Guess what - that treadmill was likely more accurate by a decent margin than your HRM.

    You've become fit enough the HRM is underestimating your burns likely, or you have the HRmax value set wrong.

    See, many reasons why it's primary purpose of monitoring your HR does NOT translate well into estimating calorie burn, since the 2 have a lose correlation.

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

    Test your HRM again.

    I have to agree with this. There are so many factors involved with getting a somewhat accurate estimate of calories burned.
    I know there's NO way the max heart rate calc works for me anymore. My fitness level has increased SOOOO much since I started this journey. My max heart rate is going to be much higher now.
    Short of going to the doctor for the treadmill test or running sprints up and down a hill with a friend monitoring me until I pass out, I have no way of knowing my actual max HR.
  • Iron_Duchess
    Iron_Duchess Posts: 429 Member
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    I personally use the Polar F6. It works quite well. :) My biggest complaint is that I can never seem to secure the strap properly and sometimes my sports bra will slip UNDER the strap, thus breaking the connection and ruining the readout. *sigh*

    I've never been able how to 100% get around that but in the meantime it works pretty well. :)

    I suspect your strap isn't tight enough. It shouldn't be able to slip, though I have had this happen once or twice with one particular bra.
    I have a Polar HRM and what I do is place the strap before putting the sports bra and make sure that the bra is completely over it. The strap never moves.
  • heybales
    heybales Posts: 18,842 Member
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    I have to agree with this. There are so many factors involved with getting a somewhat accurate estimate of calories burned.
    I know there's NO way the max heart rate calc works for me anymore. My fitness level has increased SOOOO much since I started this journey. My max heart rate is going to be much higher now.
    Short of going to the doctor for the treadmill test or running sprints up and down a hill with a friend monitoring me until I pass out, I have no way of knowing my actual max HR.

    Oh sure there is!

    You sound primed for a puke, ahem, I mean HRmax test.

    http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max

    You'll probably even need the one in the link at the bottom, the one in the post may not be enough for you now.
    It is interesting, and leads to a decently accurate VO2max stat, which is mighty useful too.
  • rose313
    rose313 Posts: 1,146 Member
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    Has anyone experienced erratic readings caused by TVs at the gym, cell phones near you, other HRMs near you, etc?

    Make sure whichever one you buy has a coded transmitter.

    Does the Polar Ft4 have a coded transmitter? I googled it but don't really understand it.
  • heybales
    heybales Posts: 18,842 Member
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    Has anyone experienced erratic readings caused by TVs at the gym, cell phones near you, other HRMs near you, etc?

    Make sure whichever one you buy has a coded transmitter.

    Does the Polar Ft4 have a coded transmitter? I googled it but don't really understand it.

    Yes, Polar is digital. Actually, both, it sends out an analog signal too most machines can pick up and display your HR. So that part could be screwed up in noisy environment, but the HRM would still pick it up correctly.
  • rapat
    rapat Posts: 108 Member
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    I bought an HRM (Polar FT7) a few weeks ago.
    My initial one wasnt working -- The HR that it showed would kind of stick. After trying to adjust the chest strap a bunch of times, I realized that the Ellpitical/Treadmills were picking up my HR (they have wireless receivers), so it was the watch that was the problem. Exchanged it and the new one works fine.

    Just mentioning that because sometimes they can be broken so its worth finding out if its the chest strap or watch so you dont spend lots of effort making tons of chest strap adjustments.

    Anyways, its nice to get the calories burned estimate for cardio. I also wore it during my hockey game to see what my max/avg hrs were.
    On the elliptical, its easy to get lazy, so either having a target strides/minute or target hr to maintain would help prevent the laziness.
  • rose313
    rose313 Posts: 1,146 Member
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    Has anyone experienced erratic readings caused by TVs at the gym, cell phones near you, other HRMs near you, etc?

    Make sure whichever one you buy has a coded transmitter.

    Does the Polar Ft4 have a coded transmitter? I googled it but don't really understand it.

    Yes, Polar is digital. Actually, both, it sends out an analog signal too most machines can pick up and display your HR. So that part could be screwed up in noisy environment, but the HRM would still pick it up correctly.

    Wow that's amazing! Thanks!
  • SteveHunt113
    SteveHunt113 Posts: 648 Member
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    A couple of things:

    I have the polar FT7. I've never noticed any interference between my watch and chest strap, but I have had interference between my chest strap and the machine I'm using that was caused by my iPhone. It was giving me a heart rate of over 200 bpm when I first got on the machine.

    Also, I believe a HRM does work well enough for circuit training, assuming you have very limited rest between exercises. I presume you do 4-6 different exercises back-to-back and then rest for 30-60 seconds? Just stop the HRM during the rest period and then start it for the next set.

    Like others have said, the more fit you get, the higher your VO2MAX becomes, which means your heart does not need to beat as fast to supply your body with the oxygen it needs. Because of this, your reported caloric burn will go down the more fit you get. There are some HRM's out there that either allow you to enter your VO2MAX, or provide a utility that tries to guess your fitness level based on your resting heart rate. These HRM's obviously are more expensive, but provide a higher degree of accuracy. As others have stated, no matter how much money you spend for a top-of-the-line HRM, you're still only getting a guess at caloric burn.

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