HIIT & Intervals BURN Calories and Keep Workouts Fun

amylynnadelman
amylynnadelman Posts: 6
in Fitness and Exercise
Hi! I have been passionate about fitness since I just joined a gym at 16 years old. 23 Years later I am still in love with working out and finding new, challenging and effective exercises. Although I have been able to maintain a comfortable weight and fitness level I really wanted to step it up in intensity and burn through those last 10 lbs. I recently joined My Fitness Pal and bought a Polar F4 Monitor and It is incredible to see how effective the program is! I get a thrill out of adding my calories burned from my HIIT Workouts! I have over 70 Workouts available if anyone is interested! I burn between 400 and 750 calories per workout! :smile:

Replies

  • phjorg1
    phjorg1 Posts: 642 Member
    Hiit by definition will not work with a hrm. So your calorie burns are inaccurate and inflated.
  • rachaelgifford
    rachaelgifford Posts: 320 Member
    Why would HIIT not work with an HRM? Provifing the HRM is working I can't see the problem?
  • rachaelgifford
    rachaelgifford Posts: 320 Member
    Why would HIIT not work with an HRM? Provifing the HRM is working I can't see the problem?

    Although - I guess with the sudden changes in heart rate perhaps it doesn't keep up?
  • Alehmer
    Alehmer Posts: 433 Member
    HIIT requires 100% energy and commitment 100% of the time, regardless of your heart rate. It's sprint-from-certain-death the whole time to really be HIIT and reap the benefits.

    The VAST majority of calorie and fat burning from HIIT is done in the 24 hours after the workout, not during it, so measuring what happens in the workout doesn't yield very accurate results.

    I usually just double or triple my actual exercise time, though it's probably worth more than that.
  • phjorg1
    phjorg1 Posts: 642 Member
    Why would HIIT not work with an HRM? Provifing the HRM is working I can't see the problem?
    Because hiit is >100% vo2max
  • DavPul
    DavPul Posts: 61,406 Member
    Hiit by definition will not work with a hrm. So your calorie burns are inaccurate and inflated.

    cosigned. don't let that keep you from enjoying your HIIT workouts though. hyper accurate calorie counting isn't required to lose weight.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    Why would HIIT not work with an HRM? Provifing the HRM is working I can't see the problem?
    Because hiit is >100% vo2max

    This.

    The formulas HRMs use for estimating calorie burns are based on steady state cardio activity at moderate intensity.

    Plus the "intervals" also affect the accuracy.
  • vorgas
    vorgas Posts: 741 Member
    Why would HIIT not work with an HRM? Provifing the HRM is working I can't see the problem?

    Although - I guess with the sudden changes in heart rate perhaps it doesn't keep up?
    It's a function of what the HRM is designed to measure.

    The first major hurdle to understand is that a beating heart is not what burns more calories. I mean, yes it's a muscle, and so will burn more calories, but we aren't talking Kilocalories here. You can test this yourself by sitting perfectly still, and holding your breath as long as you can. Repeat 3 or 4 times. Watch your HR skyrocket. But clearly not experiencing the calorie burn a HRM would indicate.

    Heart rate is an INDICATOR of underlying function. During aerobic activity, fat is combined with oxygen to produce ATP so your muscles can work. The important word here is aerobic. By definition, in the presence of oxygen.

    The correlation of your heart rate in response to oxygen demand is fairly well understood at this point. It's called Volume Load. In other words, your heart is responding to a demand for an increased volume of oxygen.

    Once your heart rate gets to about 65% - 70% the fat burning process is just too slow to provide energy. So your body turns to burning carbohydrates (sugars) as fuel. This sugar is stored in the muscles and liver as glycogen. Your heart rate has NOTHING to do with how fast or how much this occurs. Everybody is different.

    So as your demand climbs above your bodies ability to process oxygen, the relationship between volume load and calories begins to break down. Even the instructions on any decent HRM will tell you the effective range is between 50% and 70% of your max HR.

    This is why you can't use a HRM throughout the day to determine calories burned. And, coincidentally, why you can't use it to accurately tell calories burned during weight lifting (that's a Pressure Load Response, not a Volume Load).

    So, yes, during HIIT it will certainly give you a good idea of where you are calorie wise, but it's not an accurate function at all.

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