While some types of cardio machines are more precise than others, none of them will be 100 percent correct. In general, they overestimate your calorie burn by 15 percent to 20 percent because they can’t account for all the unique factors involved in calorie-burning.

Personal Calorie Burn Factors

Modern cardio machines often need you to input your personal information before they will allow you to use the machine. Your weight, gender, and age can all be taken into account when calculating your calorie expenditure. The trouble is that there are a lot of other things to consider.

Standard formulas are used to calculate the number of calories expended by cardio machines like treadmills. Calorie-burning formulas like this are easy to come up with on your own. You won’t be evaluated on things like your degree of fitness, your body composition, or your height and weight. 1

  • Fitness level: You’ll burn more calories if you’re just getting started with a new workout routine or if you’re switching from one activity to another. Burning fewer calories at the same activity for the same amount of time as you grow more fit and more efficient will occur.
  • Body composition: When you first begin exercising, you’re more likely to be made up of fat than muscle, which means you’ll burn fewer calories than you would if you weren’t exercising. With each additional pound of muscle, your body becomes more effective and burns more calories in the same amount of exercise as it did before.
  • Body size: When two people are the same weight, the larger one has the ability to burn more calories than the smaller one.
  • Age: Depending on the machine, your age may be taken into account or not. However, as you get older, your metabolism slows down and you won’t be able to burn as many calories as you used to. You can compensate for this by working out longer or working harder.

The treadmill will show the same number of calories expended for two women of the same weight and body fat percentages jogging at the same pace for a 10-minute mile, for example. The second lady, on the other hand, is burning more calories since she is leaner and has more muscle mass.

Experience and Efficiency

On a treadmill, your form and efficiency matter more than with any other type of exercise machine. These variables cannot be taken into account by the machine.

Even at the same pace and distance, new runners typically burn more calories than more experienced ones. This is due to the fact that novices tend to run side-to-side and bounce up and down a lot. Even though the extra movements are unnecessary, they use more energy than the efficient stride of an experienced runner does. In time, this will alter, but for beginners, it’s a crucial issue to keep in mind.

It’s also possible that you’re decreasing your caloric burn by using the handrails on a treadmill or stepper. You won’t be able to walk with a natural swing in your arms.

As a result of the way athletes use the devices, they also have varying levels of precision. A stationary bike, for example, restricts movement in such a way that it is used in much the same way by everyone. This is a better option than treadmills and stair steppers, which allow for more range of movement.

Wearable Fitness Trackers

Can you rely on your personal fitness tracker instead of the calorie metre on the cardio machine? You can use these popular wearable devices to keep tabs on your health and fitness, so they’re an excellent choice for keeping tabs on your workouts.

Stanford University conducted a study to examine the accuracy of seven different devices. As it turned out, the most accurate were 27 percent off, while the least accurate were 93%. The researchers found that the heart rate monitor was the most dependable feature, but the calorie counter was not. 2

Treadmill

Treadmill devotees will rejoice: When you enter your weight and don’t use the handrails, experts say, the calorie counter is pretty accurate. If you don’t know your weight, you can’t get an accurate reading, adds Olson, because many treadmills don’t ask. That means that if you weigh 135 lbs, you’re actually burning around 15% fewer calories than the machine claims you are (300 calories vs. 255 calories, for example).

As much as 40% of your reading can be thrown off by relying on the handrails while jogging at high speeds or on steep inclines (that 300 calories burned just became 180). People who can drag themselves up a hill for 20 minutes aren’t the only ones we’re talking about, though. Weight placed on the support rails can reduce calories burnt by as much as 20%, according to Olson.

Boost your burn: To get the most out of your treadmill time, stay away from the handrails and maintain a proper running stance. “Slumping over can have a huge influence on your oxygen intake, making your workout more difficult,” Cardiello explains.

Take your run outside whenever you can if you have the opportunity. “Running outside is more taxing on the body than running indoors. You can’t compare the distance and pace of your treadmill run to that of an outdoor trail run because the treadmill’s calibration and physical stress is less than that of an outdoor trail run.”

What if you can’t get outside? Increase the duration (or distance) of your indoor workout to compensate for the change in elevation, or try this fat-melting interval routine.

The Bottom Line

Be sceptical of the number of calories you think you’ve expended during your workout. Cardiello complains that too many machines fail to take into account things such as your weight, the usage of handrails, and your degree of fitness, all of which can have a significant impact. “The most important factor is [a person’s degree of fitness]. In what way can two men, one 200 pounds and the other in good physical form, burn the same number of calories? You’re wrong, they’re not!”

Monitor your heart rate or use perceived exertion to estimate how hard you’re working out instead of depending simply on calorie counts. In Cardiello’s opinion, if you’re gasping for air while trying to sing the lyrics of a song, you’re working at or close to your maximal intensity.