Are Cardio Machines Lying to You?

It can be very satisfying to see the calorie counter on the cardio machines at the gym sore up to the highest number you can push it to.  After all, you do actually want to see some immediate results from your blood, sweat tears.  Unfortunately, those machines may not be telling the whole truth.

According to Alex Hutchinson, author of the book, “Which Comes First, Cardio or Weights”, cardio machines at the gym count calories based on research from the “average” user.  The counter numbers are based on how many calories per pound of body weight is burned at different intensities. But none of us is “average.”  

Here's the breakdown:  If you have more body fat than average, you’ll burn fewer calories per pound of total body weight. That means the number on the treadmill (or elliptical or exercise bike) is an overestimate. If you’re less aerobically fit than average, on the other hand, you’ll burn more calories than the treadmill thinks. Other factors like height, age and sex also skew the results – not to mention more obvious things like using the handrails to support some of your bodyweight, which is a common cheat on the elliptical and treadmill that the machine doesn’t take into account.

But all of these factors are relatively minor compared to the most misleading part of exercise machine calorie counts: the difference between gross and net calorie burns. For example, a 176 lb. person walking for an hour at 2.5 mph will burn 240 calories, according to the treadmill counter. But if they had spent that hour lying on the couch, they would’ve burned 80 calories just to stay alive – so they really burned an extra 160 calories by exercising. That’s an overestimate of 50 percent!

The lower the intensity of the exercise, the bigger the difference between gross and net calorie numbers. If you want to make a back-of-the-envelope correction, you can subtract 1 calorie for every pound of bodyweight per hour of exercise from the cardio machine’s number. Still, that’s just going to give you a very rough estimate. For meaningful feedback, it’s probably better to focus on things like how far you went, how fast, how hard – and how it made you feel.

It's always nice to see that BIG number on the machine when you're finished, but if you're not seeing results that you expected from your cardio, now you know why.