Can I trust online calorie calculators with heart rate?

kittygrrl15
kittygrrl15 Posts: 11
in Fitness and Exercise
I'm new to trying to counting calories and using real data with a workout. (I'm also not a big fan of "working out" and generally have avoided it- but it's time to get serious here.)

My husband has an older Polar heart rate monitor that I've started wearing during my walks. (That would be the 2 walks I've done - we are not talking about months of data here!) We haven't figured out if it has a calories burned function built in, so I've been tracking caloric burn by taking my stats and plugging them into various online calculators such as http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx and http://www.calories-calculator.net/Calories_Burned_By_Heart_Rate.html.

I have no idea how fast I'm walking (and one walk I was pushing my son in a jogger- so maybe 40 lbs?) but according to those calculators, I'm burning even more calories than what MFP's database says for the 5mph walk entry, and everything I've read in the forums indicates they generally overestimate calories burned.

For example, I walked at a good clip solo last night for 39 minutes and my avg heart rate according to the monitor was 150. I hit the 180's when I boogied up a decent hill and then was anywhere from 130's to 150's for most of the rest of the walk. I felt like I was working and sweat a ton. After all, I AM out of shape. When I plug in the website info (Female, 150 lbs, 35 yrs old, 39 min, 150 avg) I get as high as 379 burned from one of those sites.

I have NO clue if that's close to being right. And I'd hate to trust it only to find out it's really off- and that I shouldn't have rewarded myself with a half slice of ice cream cake for my good work and calorie deficit.

Thoughts? I just want my info to be in the ballpark of accurate...

Replies

  • 4legsRbetterthan2
    4legsRbetterthan2 Posts: 19,589 MFP Moderator
    I have a polar and it will tell me the calories I burn on another screen. I do not know what model you have but I would suggest looking up the user manual for yours online. I image you may also need to reprogram it since you said it was your husbands. When I got mine I set it up to my weight and height so those numbers are being included in the calorie calcultions if it is doing them.

    If you have a smart phone I like an app called runkeeper, it is free and will use the gps on your phone to track your runs (or walk). It will tell you the distance you covered, your pace, and it calculates out your calories burned. I found it to be pretty in sync with my HRM so I trust it. You can link it to your MFP account and it will automatically put the workouts it tracks into your MFP. That might be another option if you cannot get what you want out of your polar.

    Hope that helped, happy walking :)
  • Uniquelydezigned
    Uniquelydezigned Posts: 1
    First, congratulations on wanting to get healthier.

    I recently found a calculator on Jillian Michael's website that can help you manually calculate your calories burned.

    C = [(.4472 * H) - (.05741 * W) + (.074 * A) - 20.4022] * T / 4.184
    C = calories
    H = average heart rate
    W = weight
    A = Age
    T = Time

    Using this equation, it looks like you would burn approx 379 calories in 39 minutes. However, this doesn't take into account your VO2Max, which you find using your resting heart rate. Once you have that information, you can use the online calculators to better figure out how many calories your burning while working out.

    Hope that helps.

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