Trusting my HRM

So I just got a Timex HRM that has a chest strap and counts calories. So far I love it, but its telling I've burned a ton of calories today while bike riding. I dont know whether i can trust it. I know I am not the most fit person and I did push myself and I rode for an hour, and I live in Colorado so the terrain is not flat but its telling me I burned 781 calories. That seems like a lot. Do you think it is safe to trust?

Replies

  • fishgutzy
    fishgutzy Posts: 2,807 Member
    For Colorado terrain it is probably accurate. Florida flat rock terrain would be lower. :)
  • Mokey41
    Mokey41 Posts: 5,769 Member
    Timex is notorious for over estimating calories for women. They use the same algorithms as for a man.
  • RepsnSets
    RepsnSets Posts: 805 Member
    Golly that seems like a heck of alot of calories. Are your settings all correct? Weight? height etc etc?
  • irjeffb
    irjeffb Posts: 275 Member
    I use a Polar, and I assume that it overestimates. That's the primary reason that I only eat back HALF of my exercise calories.
  • Fitness4Paul
    Fitness4Paul Posts: 166 Member
    You do burn a ton of calories riding a bike. Also, your burn is higher when you're not in the best shape because you're body is working harder. For example, If you rode for 10 at 12 MPH your heart rate might have been averaging 170-180. Doing the same ride once you've conditioned your body you might find your average heart rate to be lower, like 150-160. Since the calorie burn is calculated by a heat rate monitor is based on heart rate you'll see more calories burned as you're body is working harder.
    That's how I understand it at least.
  • misssiri
    misssiri Posts: 335 Member
    I bought a Timex in the beginning and I felt it overestimated but because I had my calories set to 1200 plus exercise calories and I was always hungry, I still ate ALL of them. And I still lost 1lb a week on average. I did eventually get a polar and I do feel it is more accurate. I trust it enough to eat all the calories back and am maintaining with no problems.
  • evdenapoli
    evdenapoli Posts: 164 Member
    I have the Timex as well. I was worried about that as well. But When I use it while on my elliptical or stationary bike the numbers are similar to what the machies read..However, it is more accurate when you set your Target heart rate zone. If you leave it as "Manual" i find the numbers way high
  • That is how I estimated how accurate my HRM is. I got on the elliptical at the gym and compared the calories burned, very close, so I trust my HRM.
  • swashburn3
    swashburn3 Posts: 172 Member
    Maybe check it against this: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

    And be sure to use NET calories since MFP already tracks your BMR calories.
  • Stephy2469
    Stephy2469 Posts: 35 Member
    that sounds about right. With my oregon scientific I burn nearly 400 every half hour and that's on my stationary bike.
  • Mokey41
    Mokey41 Posts: 5,769 Member
    That is how I estimated how accurate my HRM is. I got on the elliptical at the gym and compared the calories burned, very close, so I trust my HRM.

    Machines usually give very generous readings as well so it isn't a good way to decide on accuracy.
  • amandapye78
    amandapye78 Posts: 820 Member
    I have the Timex as well. I was worried about that as well. But When I use it while on my elliptical or stationary bike the numbers are similar to what the machies read..However, it is more accurate when you set your Target heart rate zone. If you leave it as "Manual" i find the numbers way high

    I did set my Target heart rate zone. I know my heart rate was high and all of the settings are correct
  • amandapye78
    amandapye78 Posts: 820 Member
    Maybe check it against this: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

    And be sure to use NET calories since MFP already tracks your BMR calories.

    This said about 618 so it wasn't as far off as I thought. I was only going to eat half and go with that.
  • my personal trainer suggested averaging the myfitnesspal calorie burn number with my heart rate moniter number for each exercise, it seems to be working out for me so far!
  • amandapye78
    amandapye78 Posts: 820 Member
    my personal trainer suggested averaging the myfitnesspal calorie burn number with my heart rate moniter number for each exercise, it seems to be working out for me so far!

    Oooh, I'll try that. That may work
  • My old HRM (Garmin from 2011) used to give me really low calorie numbers, and my new one (Garmin from 2013) is really high. What the treadmill and MFP read is somewhere in the middle. Which one should I go with?