The calorie counter on your favorite exercise machine probably can’t be trusted? Say it ain’t so!
What’s worse — your wearable fitness device can’t either. According to a study by the University of California at San Francisco, exercise machines overestimate calorie burning by 19 percent, while watches clock in around 27 percent.
“The problem with mechanical calorie counters is that they don’t account for all factors,” says Brian Lehner, a certified strength and conditioning specialist and exercise instructor with the Sewall Healthy Living Center at Sharp Coronado Hospital. “Height, weight, age, fitness level and body fat percentage are missed altogether.”
When it comes to accurately counting calories, some machines are better than others. Machines that allow for more personalization garner more accurate results. But most gym machines give roundabout estimates, serving more as loose guides than bold targets.
Accuracy varies by type of machine too:
|Machine||Average percent error|
|Stair stepper||13 percent|
|Stationary bike||7 percent|
When it comes to readers on wearable fitness devices, there’s good news and bad news. Yes, on average, the calorie counter is inaccurate — a recent study showed the worst on the market with a 93 percent error. But in good and arguably more important news, wearable heart rate monitors are generally spot-on.
Does this mean you should ditch devices and machines altogether? Of course not. Your counter may be wrong, but your exercise goals are still very right. Quantifying those goals will just take a bit more work.
“Let’s say you’re trying to lose weight,” says Lehner. “Your calorie counter says you burned 500 calories, so you eat 500 calories of extra food. Does your weight increase or decrease after a couple of weeks of this? Depending on what your goals are, we can then adjust.”
At the end of the day, exercise goals are more of an art than a science. Eating healthy, staying active and managing stress all do their part in your physical well-being. So putting a focus on your progress, and not an electronic counter, gives you the strength and power you need.
“All we’re doing is collecting information to make the best decisions moving forward,” says Lehner. “You don’t need a calorie counter to tell you that. If you know you are moving toward your goals, then keep moving forward. And if you feel discouraged or don’t seem to be getting where you want to be, reach out to an exercise specialist. We’re always here to help.”
The Sewall Healthy Living Center at Sharp Coronado Hospital offers monthly and annual memberships, group fitness classes and personal training. Learn more about Fitness Center offerings.