Does this # sound right or is my HRM wrong?

nrheasley
nrheasley Posts: 78 Member
in Fitness and Exercise
My workout today was an hour and a half long. The first 45 minutes was an interval run. The second half was 3 sets of squat-thrusts (burpees), lunges, and squats for a total of 30-40 of each exercise. Normally, I would stop my HRM after the interval run and restart it it before my strength training. Today, I just let it run the entire time without stopping it midway just to see what would happen. It told me I burned 641 calories! My average workout is only 500. I know I did things a little differently today-besides letting my HRM run the full workout, I kicked up the speed and incline on the run a tad bit, and I threw in a few extra sets during my strength training--but does that number sound too high?

Replies

  • brianpperkins
    brianpperkins Posts: 6,124 Member
    You're using a HRM for exercises where there are no established relationships between HR, VO2 max, and caloric burn. It isn't that your HRM is wrong, it's that you're using it for things it cannot possibly calculate.
  • nrheasley
    nrheasley Posts: 78 Member
    Can you explain that a little better? Which exercises would you not use a HRM for?
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    Can you explain that a little better? Which exercises would you not use a HRM for?

    HRMs are only relatively accurate for calorie burn for steady start aerobic work. The further you get from that, the more error there will be in RE to calorie burn. They are pretty much useless for strength training as spikes in your HR are going to tell the HRM that you all of a sudden burned a bunch of calories...but that's not how it works. You calorie burn is not directly attributable to HR...if it was, I'd just have someone walk into my office every five minutes and say, "BOO."

    Your HR is simply used in an algorithm that assumes a steady state aerobic event as a steady state aerobic event is a reasonably good marker for some % of your potential VO2 max and to what extent you are working towards that...i.e. the higher your HR, the monitor assumes you are working towards a higher and higher level of VO2 max. Resistance/strength training is an anaerobic activity an there is no relationship between that and your VO2 max...thus a HRM is pretty much useless for determining calorie burns during this type of activity.
  • nrheasley
    nrheasley Posts: 78 Member
    Thank you for the info! So how would you recommend I track calorie burn during my workouts?

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