How Accurate are the Calorie Counts on Treadmills?

People exercising in health club
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Many runners wonder if the calorie trackers on treadmills and other cardio machines are accurate. If you enter your weight before you start your treadmill run, the calories burned count is really just a rough estimate and will never be completely accurate. Cardio machines such as treadmills use standard formulas to figure out the amount of calories burned. But the calculations don't take into account important factors other than weight, such as body fat percentage and fitness level.

For example, if a 160-pound woman with 35% body fat and a 160-pound woman with 20% body fat are both running at a 10:00/mile pace, the treadmill will display the same amount of calories burned. However, the woman with the lower body fat and more muscle mass is actually burning more calories.

Treadmills also don't take your form and running efficiency into account. New runners will usually burn more calories than more experienced runners running the same pace and distance. Why? The beginner's inefficient side to side movement and bouncing up and down expends more energy than the experienced runner's efficient stride. So if a newbie runner and an experienced runner are going the same speed (assuming the same body fat percentage), the beginner may actually be burning more calories than the experienced runner.

Some reports suggest that treadmills and other cardio machines actually overestimate calories burned by up to 15% to 20%.

So it's important that you take the calories burned readings with a grain of salt. It's fine to use the numbers as a benchmark for your runs, but don't plan on consuming additional calories based on that number. That's an easy way to start gaining weight, despite your exercise efforts.

The bottom line is that you should assume the number on the treadmill is an overestimate.

If you really want to get a better idea of how many calories you're burning during your runs, try using a heart rate monitor or an activity tracker. They're usually more accurate than cardio machines.

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