Don't Count on Calorie Counters

Jan. 14, 2008 — -- It's January, and for most of us, that means going back to the gym to sweat off those holiday pounds. But if you're using the gym machines to count your calories, you're in for a big surprise.

Many rely on calorie counters in their quest for the perfect body, but unfortunately it's not an exact science and the numbers you're seeing are not the whole truth.

For 54-year-old Cynthia Goldberg, 600 is the magic number of calories she wants to burn to erase Sunday night's dinner.

"I had some wine, had some pasta, so that's on here now so I've got to work it off," she said. "I really try to see the numbers to know that I'm on the mark."

Doctors say though that the numbers don't add up.

"There is absolutely no way those machines can accurately determine the amount of calories that they burn," said weight specialist Mitchell Roslin.

Roslin says most machines overestimate the number of calories burned by 10 percent to 30 percent— some as high as 50 percent.

Goldberg was not shocked to hear the news. "That's why I haven't been able to get this off," she said with a laugh.

Most machines also don't account for body fat. For example, if two people weigh the same, the one with more fat will burn fewer calories than the person with more muscle mass.

Mal McHugh from the Nicholas Institute of Sports Medicine says beyond calculating this complicated mathematical formula, there's really no way to be sure exactly how many calories you're burning: "It's not that simple."

Experts agree that some counters are better than others: weight-bearing machines like treadmills and Stairmasters are more accurate than stationary bikes that don't factor in weight.

The way to get the most bang for your sweat is by using a heart monitor. The goal is to reach a breathing intensity where you can still carry on a conversation but with some difficulty, then note your heart rate at that level.