Is Using a Stair Machine the Same as Climbing Stairs?

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 calorie”: chemists confusingly use a calorie measure that’s 1,000 times smaller.) Of course, in physics we prefer to measure energy in joules. Just to give you a feel for this unit, if you lift a textbook from the floor to a table, that would take about 10 joules. Now, the work-energy principle says that in order to change the energy of a system, you need to add energy to (or remove en ... Read full article.