Formula for Calories Burned
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Calculating Calories Burned During Workouts

Revised 7/22/2014

“How many calories do you think I burned during my workout today?”

That’s a question I get just about every day.  After all, most people work out so they can burn calories.  They want to track the calories they burn throughout the day and compare them with the calories they consume so they can create a caloric deficit, thus leading to weight loss.  I can only estimate based on what I’ve been able track with my own workouts and calculations.  There are several factors such as age, weight, heart rate, and intensity of the workout.

One way that people can calculate calories burned is by wearing a heart rate monitor.  This can be either a sports watch, a chest strap with wrist monitor, or there’s even a chest strap that sends data to your smart phone via Blue Tooth technology.  However, these may not be accurate.

Sport watches might not be accurate if they lose contact with your wrist during a workout.

One problem with the sports watch is that the back of the watch or back of the transmitting device must remain in constant contact with the skin on your wrist or your chest.  If it’s not making contact, it doesn’t calculate.  I’ve found that when I sweat or do certain exercises, that contact is broken and my watch is no longer monitoring my heart rate, thus missing calories burned.  I’ve often found that “calories burned” number on my watch to be quite a bit less than what I manually calculate following a workout.

I need to also point out that the readouts of calories burned that you see on treadmills, elliptical machines and other cardio equipment are just general estimates.  Most are not sophisticated enough to factor in your age, height, weight, body fat percentage, etc…  So, don’t rely on these numbers if you are trying accurately calculate how many calories you burn.  Some overestimate calories burned by as much as 40%!!!

One of the more standard and most accurate ways to calculate the equation is to use the calorie expenditure formula below .  It comes from the Journal of Sports Sciences and provides a formula for each gender.

Men use the following formula:

Calories Burned = [(Age x 0.2017) — (Weight x 0.09036) + (Heart Rate x 0.6309) — 55.0969] x Time / 4.184.

Women use the following formula:

Calories Burned = [(Age x 0.074) — (Weight x 0.05741) + (Heart Rate x 0.4472) — 20.4022] x Time / 4.184.

Calculation

For example, here’s my formula  based on a 49 year old male weighing 155 for a workout where my heart rate averages about 148 bpm throughout a 60-minute boot camp workout.

[(49 x 0.2017) — (155 x 0.09036) + (148 x 0.6309) – 55.0969] x 60/4.184 =

[9.8833 — 14.0058 + 93.3792 – 55.0969] x 14.3403 = 489.47 calories (or 15 kcal/min)

I hope you find this formula helpful. As always, check with your physician, nutritionist, or a certified personal trainer if you have any questions or desire more accurate testing and results.

To your health!

This entry was posted in Injuries and Conditions, Miscellaneous, Programming, Workouts. Bookmark the permalink.

6 Responses to Formula for Calories Burned
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  1. tony greenwood says:

    hi , excuse my ignorance. i do 70 minutes on a treadmill at a incline 15 (15degees) @6.5 k per hour. the treadmill registers 1230 cals. my polar registers 600 ish.what one is nearest the truth???

    thanks in advance
    tony greenwood

  2. Brian Koning says:

    Tony,

    Machines don’t take into consideration your body type, height, weight, age, etc… If you programmed your stats into your Polar, then that’s going to be more accurate. I usually figure between 8-10 calories per minute in an average heart rate zone of about 135 bpm – 165bpm. So the “600″-ish is about right and may be a little low, depending on your effort.

    Brian

  3. Can you re-ceheck your sources please? Is it:

    [(Age x 0.2017) PLUS (Weight x 0.09036)

    or is it

    [(Age x 0.2017) MINUS (Weight x 0.09036)?!?!?

    You have it as PLUS for men, but MINUS (if that’s what “–” means) for women.

    Livestrong.com has it as MINUS for both. Or at least, they use “–”, which I’m assuming means MINUS.

    BIG difference in the outcomes.

    • Brian Koning says:

      Michael,
      On this one, Livestrong.com is wrong. If you go to that page and then look at the comments, you’ll see that several people called them out for being wrong on the male calculation which should be “+”. I caught it when I started calculating using Livestrong’s formula and it didn’t make since since the calorie burn decreased as body weight increased. The calcualtion for women is correct with “-”. Not sure why Livestrong still hasn’t made the correction. Here is a link to those comments.

      http://www.livestrong.com/article/221621-formula-for-calories-burned-during-exercise/#comments

      Hope that helps!

  4. Patrick McMotrik says:

    How can the above formulas be correct ? If you insert data for a whole day (1440 minutes, at a resting pace, the results get way too high ?

    If the formulas are not suitable for a whole day calculation, what is the maximum duration that fits the formulas ?

    Does any formulas exist, that works for any duration (ie a whole day) ?

    • Brian Koning says:

      Patrick,
      You are correct. There was an error in the formula for men. It should have been a “minus” sign between the “age” and “weight” portion of the formula. I adjusted the other calculations. One of the problems that I see with this formula, however, is that it only accounts for calories burned during the workout and does not figure in EPOC resulting from High Intensity Interval Training. Those extra calories burned are just as important because of the increased metabolism generated for several hours post HIIT. Thanks for bringing this error to my attention.

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