You could be burning fewer calories at the gym than you think.

In a study published in 2018 researchers found that some ellipticals overestimate calories burned by as much as 130 calories for 30 minutes of exercise.

Now, to put that in perspective, if you ate an extra 130 calories of food each day, you'd put on more than a pound each month or 13 £5 a year.

And as it turns out, ellipticals aren't the Onley machines with imprecise calorie counters.

Well, when you talk about the calculations, here they are way off s Oh, they are so much off You can't really use the information, meaning that it can be more than 50% off.

Now, for some, counting calories isn't the point.

They're in it for the other benefits exercise offers.

But for the nearly 50% of Americans who have at some point tried to lose weight, it really does matter.

And that's because people might eat more when they think they're burning more calories.

The participants in the group that had fitness trackers, Fitbit monitors they actually didn't lose as much weight as the people that didn't have anything on one recent.

It all might be that they were over estimated in terms of energy expenditures, so they allowed themselves to eat more and therefore didn't lose.

Lose as much weight.

Now the formula for losing weight may look simple.

Burn more calories than you consume, but actually measuring calories isn't at least on your typical exercise machine.

The reason it's so difficult to get the calorie counts correct is that you're not really measuring the calorie counts.

So to do that you need thio.

Measure all the cells in your body and how much energy they are using, and obviously you're not going to do that.

So instead, you try to do some other proxies for that so you might measure the distance you're traveling or you might measure your heart rate.

Do you might measuring something else?

Three.

The power output on the elliptical, for example, according to Mattson, it largely comes down to how well each machine calculates that power output, which is a relatively reliable proxy for calories and the more complex and machinists.

So Stairmaster, in a elliptical, is more complex than a bike.

The less accurate the power output will be.

For one study, researchers compared calorie readouts for ellipticals, stair climbers, stationary bikes and treadmills.

The calorie count on ellipticals was off by 42% while the other equipment had a noticeable but smaller margin of error.

Now, entering your weight before working out is a simple way to increase the accuracy.

And that's because different bodies burn calories at different rates, even if they're doing the same activity.

But even if you do, there's still plenty of room for error.

For example, the machine might not be well calibrated.

The power output needs to be calibrated, probably way more often than most of the normal gyms are doing it.

Today s.

So if you're running on a treadmill, if that treadmill is saying that you're doing six kilometers when you actually ran five, then obviously the calorie count will be off.

And what about using heart rate monitors?

Are those any better?

Not really.

In a study published in 2017 Mattson tested the calorie counters of several risk born monitors.

The most accurate one was off by an average of 27% and the least accurate.

It was off by a whopping 93% which can translate to hundreds of calories.

And those heart rate monitors built into exercise machines at the gym might be even worse, he says.

Now, that's not to say you should ignore calorie counters altogether.

They can be helpful for measuring your progress if you stick to the same machine at the gym.

But unless you're writing a well calibrated stationary bike, the truth is you're unlikely to get an accurate count.