HRM vs Treadmill Calories

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awnye
awnye Posts: 15
in Fitness and Exercise
Ok, so I know this question has been asked before but reading though diff posts I'm getting very different answers.

I understand that both are estimates, and that neither are 100% accurate! But the discrepancies are large.

I got a HRM today (Polar FT4) and used it today while on the treadmill.

To my surprise the treadmill picked up on it and was reading my heart rate from my HRM! Neat! (so they were reading the same number for that)

But as I went I noticed that my HRM was saying I burned a lot more Cals than the machine.

I set up the HRM with my age, weight, gender, and height. The treadmill asks for age and weight.

After 60 mins of doing about 3.8 mph with changes in gradient to keep my HR at 155 these were the Calorie readings:

HRM: 491 Cal
Treadmill: 268 Cal

That's 200 Cal + difference :| that's like a meal!

So here is my problem, I can play it 'safe' and put in the lower one but then people swear left and right that you need to eat back your exercise cals, and if i use the higher number I could be eating over by more than 200 Cals... which being that I'm really small could make a big diff for me.

Also I don't understand how people say that your height is not a factor in calculating this... but at the same time say if you are more overweight you will burn more cals... I'm only 5 foot so my 125 lbs is more 'overweight' than someone who is 5 foot 5 or more. :\

What would you/do you do?

Replies

  • thepiratemd
    thepiratemd Posts: 65
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    edit- I used to think I was getting 400 calories from my treadmill workouts

    then I had a very seasoned sprinter tell me that was nowhere near accurate. they burn about 500 calories froma 20 minute intense session.

    a normal jog a person would do on a treadmill (5mph) is closer to 250 calories
  • bbbgamer
    bbbgamer Posts: 582 Member
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    don't eat because someone tells you to...
  • Azdak
    Azdak Posts: 8,281 Member
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    1. If you are holding on to the handrails, then your TM calories are overestimated. However that does not mean your HRM is accurate.

    2. If you are not holding on and your HRM calories are higher than your treadmill calories, then your HRM is not set up properly. Either your actual max heart rate is higher than the age-predicted max heart rate the HRM calculated for you OR the HRM thinks your fitness level is much higher than it is (or both).

    3. Commercial treadmills (and many home models as well) have receivers built in that can receive the signal from a chest strap and display heart rate on the console. However, heart rate is NOT used in any way to determine the calorie display on the treadmill. (Treadmills don't need heart rate because they measure actual workload, and, for steady-state treadmill walking, actual workload gives more accurate calorie estimate than heart rate).

    4. The "eating back exercise calories" is a common belief, but it is not necessary for many people--and it certainly not necessary to eat 100% of the calories back. This is one of those cases where "conventional wisdom" is wrong as often as it is correct.
  • awnye
    awnye Posts: 15
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    I wasn't holding the hand rails once I saw that it was picking up on my HR. It's strange that you say that the machine dosn't use it because it sure is insistent on me giving it because it automatically adjusts the incline of the machine to keep the work load at a point where my heart rate will stay the same (did I explain that right)?

    I'll have to look into how to change things for the HRM because I followed the instructions for setting it up so I'm not sure what more I could do.

    I suppose I can just use the lower number and call it good, though I have been intending to take the jogging/running outside instead to the treadmill but then I wouldn't have the "lower" number to go by.
  • jennyann117
    jennyann117 Posts: 34 Member
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    I have the Polar FT4 also. I've noticed that if I don't change the speed and/or incline on the treadmill, my calorie burns are pretty close. When I vary my treadmill workout, my HRM is usually 50 -75 calories burned LESS than what the treadmill states. When I use the arc trainer, my HRM calories are usually over 100 calories less than what the machine says.

    I always go by the lower number burned -which is always my HRM cals.
  • awnye
    awnye Posts: 15
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    I think I may also have a higher than normal HR? I'm not super sure. i've been to the Dr. a few times in the last year and they always take my pulse and never say anything is strange so I'll have to try taking my HR early in the morning....

    but doing the treadmill at 3.8 MPH at and average of 1.5% incline my heart rate stays right about 155, If i try and bump it up to like 4.5 MPH my HR jumps to like 180 and if i really try and run like 5 MPH I have seen my HR go over 190. At 155 I get quite the sweat going so I feel like I'm working at an ok level.

    From what I gather this is most likely a result of the fact that I have only been doing any sort of cardio activity for about a month and a half now and am out of shape. And while it has started to *feel easier* I haven't seen a change in my HR.

    Could it be that the HRM is just going to be of because im *out of shape* therefore my heart rate is higher at 'lower intensity' that probably an average person?
  • thepiratemd
    thepiratemd Posts: 65
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    if you had genetically high heart rate, you would notice it at rest. I've seen many patients with genetically LOW heart rates, but having persistent tachycardia isn't too common unless there's something more severe going on.

    I wouldn't worry if your heart rate spikes while you're solely exercising. I admit that 190 is pretty high for 5 mph... conventional wisdeom says "max" heart rate is 220- age (this calculation is actually a load of BS, but it's helpful to judge exercise effort).

    As you said it's probably because you were out of training. I had a coach tell me once that every week of inactivity can cost you 2-3 weeks or cardiovascular training, depending on your fitness level. Some of these elite atheletes could lose a TON of progress simply taking a week off to recover from an injury.
  • aarilynn
    aarilynn Posts: 74 Member
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    If you get your heart rate up high and then lower the intensity (walking) on the treadmill and your HR is decreasing fast, then you're probably getting in better shape. If it's taking a while to recover, then it's likely you're burning a lot of calories. I don't trust machines at all. I can get on a spin bike and it's always double of what my HRM says... one machine even when putting in my stats gives me super low numbers as well (it may be because its an older machine, who knows). I go with my HRM monitor and take one calorie off of each minute I workout. So if I workout for 60 min and burn 400, I minus 60 and login 320 calories. That a way I don't overeat back more than I actually burned because I don't trust my polar HRM completely esp because it doesn't factor in what I would burn not working out.
  • zanne54
    zanne54 Posts: 336 Member
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    I'm also confused. I just got a HRM and wore it for the first time yesterday for my C25K W7D2 run. When I downloaded the data, it claimed a 798 calorie burn vs. MFP's 420. I walked briskly for 5 min to warm up, ran 25 min, and then cooled down for 15 min. That's a HUGE difference.

    And I did read the manual - twice. There's quite a steep learning curve with all the terms, and zones, etc. and I'm just not retaining it yet. Hopefully I'll figure it out soon...sigh.

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