If you're watching your waistline, you probably already know that taking the stairs can help you burn calories. But not everyone climbs stairs the same way. For example, there are those pesky over-achievers who take the stairs two at a time--they must be burning more calories for all that extra effort, right? Well, not so fast. These scientists set out to test whether taking the stairs two at a time really does burn more calories. And while we won't spoil the punchline entirely for you, let'
