How Accurate Are Exercise Machines?

They crunch your calories, calculate your distance and tabulate your heart rate, but how accurate are those exercise machines on the floor of every gym? Sixteen percent of Americans belong to a health club, and many rely on the machines to keep track of calories burned, distance traveled and heart rate reached. Despite a still-faltering economy, health club memberships have increased by more than 10 percent over the past three years -- 50.2 million Americans belong to a health club, according...Full Story