Thursday, December 20, 2007
Don't Count Calories!!
Exercise physiologists say there is little in the world of exercise as wildly exaggerated as people’s estimates of the number of calories they burn.
Despite the displays on machines at gyms, with their precise-looking calorie counts, and despite the official-looking published charts of exercise and calories, it can be all but impossible to accurately estimate of the number of calories you burn.
You can use your heart rate to gauge your effort, and from that you can plan routines that are as challenging as you want. But, researchers say, heart rate does not translate easily into calories. And you may be in for a rude surprise if you try to count the calories you think you used during exercise and then reward yourself with extra food.
One reason for the calorie-count skepticism is that two individuals of the same age, gender, height, weight and even the same level of fitness can burn a different amount of calories at the same level of exertion.
Even if you wanted to get a rough estimate of the calories an average person your size might burn at the gym, you might not want to trust the displays on cardio machines, with the possible exception of treadmills, said William Haskell, an exercise physiologist at Stanford. And with treadmills, the calories are not accurate if you hang on the bars.
Dr. Haskell once studied people using treadmills. Hanging onto the rails reduced the number of calories burned by 40 to 50 percent. The same thing happened with stair-climbing machines.
As for the calorie counts on machines like stationary bicycles and elliptical cross trainers and stair climbers, all bets are off, researchers said.
A major problem is that the machines get out of calibration. “They drift in speed and grade,” Dr. Haskell said. “If you go from one machine to another, it is obvious that at the same setting you are working much harder on one and much less on the next.”
SOURCE
Despite the displays on machines at gyms, with their precise-looking calorie counts, and despite the official-looking published charts of exercise and calories, it can be all but impossible to accurately estimate of the number of calories you burn.
You can use your heart rate to gauge your effort, and from that you can plan routines that are as challenging as you want. But, researchers say, heart rate does not translate easily into calories. And you may be in for a rude surprise if you try to count the calories you think you used during exercise and then reward yourself with extra food.
One reason for the calorie-count skepticism is that two individuals of the same age, gender, height, weight and even the same level of fitness can burn a different amount of calories at the same level of exertion.
Even if you wanted to get a rough estimate of the calories an average person your size might burn at the gym, you might not want to trust the displays on cardio machines, with the possible exception of treadmills, said William Haskell, an exercise physiologist at Stanford. And with treadmills, the calories are not accurate if you hang on the bars.
Dr. Haskell once studied people using treadmills. Hanging onto the rails reduced the number of calories burned by 40 to 50 percent. The same thing happened with stair-climbing machines.
As for the calorie counts on machines like stationary bicycles and elliptical cross trainers and stair climbers, all bets are off, researchers said.
A major problem is that the machines get out of calibration. “They drift in speed and grade,” Dr. Haskell said. “If you go from one machine to another, it is obvious that at the same setting you are working much harder on one and much less on the next.”
SOURCE
Labels: Calories, exercise, fitness, myths
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