You can get a great workout by walking up the stairs in a tall building. The only problem is that you can’t watch TV while doing it—hence the popularity of stationary stair-climbing machines. But is it the same? If your goal is to burn calories, does it make any difference which you choose? That’s actually a great physics question, and we can get a pretty good mental workout with it. Shall we?
The Work-Energy Principle
OK, what is a calorie, anyway? It’s a unit of energy, defined as the amount of energy needed to raise the temperature of 1 liter of water by 1 degree Celsius. (This is your common “food