Are Exercise Machines Lying?

by WiredBerries Editors — August 10, 2007

Think you burned off that half-pint of mint chocolate chip when you've actually worked off only a chip or two? How accurate are the calorie counters provided by exercise machines? The stats provided by treadmills and stationary bikes are considered more accurate than newer-to-market machines such as elliptical.

Newer machines that ask for your weight, height, age, and gender and track your speed, intensity, heart rate, and duration of exercise provide the closest approximation of calorie burn. Gregory Florez, spokesperson for the American Council on Exercise clarifies, though, that the "calories burned" readout on any exercise machine is an approximation. In fact, some older machines can overestimate calorie burn by as much as 25%.

Miriam E. Nelson, PhD, of Tufts University, and the best-selling author of the Strong Women book series, explains that "Fitness equipment manufacturers create an 'average user' profile to determine the calculations. But different people performing the same exercise can burn calories at different rates, which can complicate accurate measurement. For instance, you'll burn more calories if you are new to an activity or if you have a higher percentage of muscle mass versus fat."

The reality: Use the stats provided by the machine as a motivational tool but pay attention to how hard you're working to determine whether you're getting a good workout.