Counter intuitive

Men's Fitness, Sept, 2004

How exact are those calorie counters on cardio machines?

Calorie counters provide estimates that are close enough for most people, but even quality machines tend to overestimate the burn by about 10% to 15%, says James Ryno, founder of the Lakeside Trainers Club in Oakland, N.J.

Manufacturers know their machines aren't accurate. That's why most elliptical trainers and stair climbers will ask you to enter your weight before you begin your workout. The idea is that, by knowing how much you weigh, the machine can more accurately estimate your calorie burn.

The problem is, whatever calculations your treadmill makes, the numbers are just generalizations. Since a treadmill or stair climber can't see if you're swinging your arms or working out harder by carrying weights, they can't be 100% accurate.

Ryno's suggestion for getting the best possible readings: Never lean on a machine while using it, type in a weight 10 pounds heavier than your actual weight at the start of your workout, and, if you must burn a specific number of calories each day, work out until you reach that number and then go a few minutes longer.