Cardio Machine Calorie Trackers

A recent article in the Globe and Mail took aim at one of the most popular parts of modern gym equipment – the calorie tracker.
That’s the little readout that tells you how many calories you have burned since the last chair was tossed across Jerry Springer’s stage and the first commercial break of Oprah. It makes sure to pop up with an update every minute or so, that is, if it isn’t on all the time.
It gets you to do crazy things. For some it is a constant challenge to get a few more strides in or an extra minute or two on the bike. For others it is a great excuse to quit working once you hit a pre-determined goal. And some people love the checks and balances system; “the little machine says 400 calories, that will take care of a good chunk of that double down I am going to eat later, perfect!”
Whatever reason you are using it there is one thing that is true for all of you – it lies.
Sorry. Hate to be the bearer of bad news (actually, no I don’t) but that little calorie display is not accurate at all. Not really even close. Here’s why.
You jump on the treadmill and enter your weight before attaching the safety strap and busting out enough steps to keep your mind somewhat stimulated as it endures another Oprah segment of somebody crying for something. And that’s it. You enter your weight and away you go.
But it simply isn’t possible to accurately determine calorie burn for a human based simply on weight. There are so many other factors that must be incorporated that it is impossible the little counter is accurate.
Calories burned are going to be a function of how fast your metabolism speeds along naturally and how hard you exercise. In addition here are other factors that affect the number of calories you will burn:

  • Age
  • Sex
  • Height
  • Muscle mass
  • Bodyfat percentage
  • Exercise experience
  • Time of day
  • Exercise intensity
  • Your metabolic type
  • Heart rate

And that list isn’t exhaustive.
What the machine manufacturers have done is take a basic formula based on an average person (usually male) working at average intensity and plugged it onto a little computer chip which then gives you the perfect Pavlonian reward system. Those little red numbers climb up the longer you make the machine work.  The machine doesn’t factor in all the other data needed to accurately predict calorie burn.
*(As an aside it should also be noted that currently accepted formulas for how many calories burned during activity are under debate in the scientific literature as we speak. This means that not even the researchers really know exactly how many calories anyone is burning or how many calories different exercise modalities actually burn).
Think about this. A 24 year old athletic male who has been training for the Olympics since he was 14 and weighs 175lbs, steps on the treadmill and does a 30 minute jog at 6 MPH.  Treadmill says he blew through 450 calories.
Right after a 45 year old woman who has been exercising for 2 months as a part of the first ever fitness program she has ever done steps onto the treadmill. She also weighs 175lbs and completes a 30 minute jog. But this is the first time she has made it 30 minutes at 6 MPH which represents the culmination of her fitness goals when she joined the gym. The display says…450 calories burned.
You may not be and exercise specialist (I am) and might not see the problem here. I will tell you. The young man will have blown the woman out of the water in calorie burn, his metabolism , training experience, age, hormone levels, and muscle mass all mean that he will have consumed far more energy than our female example. Yet the machine has no idea.
She did not burn as many calories as he did. Period.
I could make up examples all day. The facts are that you can’t trust that little machine.
It is also important to think about which formulas got plugged into that little data device. Do you think the manufacturer used the estimated metabolic rate of a de-conditioned 60 year old woman new to exercise? Or do you think they used the formula more accurate for younger male with some training experience? He would burn way more calories. What do you think is going to sell more elliptical machines?
It is actually very challenging to measure true calorie expenditure and takes a lot of equipment and a lot of smart people with nifty little mathematical algorithms.
What is the moral here? Don’t use the number off the machine to justify adding a second helping of dinner because ‘you deserved it’. Because most likely the little red glowing number making you feel so good about yourself is most likely about as accurate as the results your gym promised you for simply signing the contract.

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