Welcome to brain Stuff from how stuff works dot com where smart Happens. Hi, I'm Marshall Brain. Have you ever been to the gym and used a piece of equipment that tells you the number of calories that you've burned? The New York Times ran a story this week explaining how bad these calorie estimates really are. Intuitively, we know that these estimates are often wrong. Here's how we know that. It's easy to jump on a ster machine and have it tell you that you've burned a thousand calories in
half an hour. But here is the comparison you have to keep in mind. Imagine that you go out running and you run ten miles in one hour. That is ten six minute miles. Most people couldn't even do it. If you could do it, imagine how you would feel that ten mile run is, roughly speaking, when thousand calories burned. You would have to feel that bad to burn a thousand calories. And even that is a rough estimate because it changes wildly depending on how much you weigh, how
old you are, and things like that. So you have three things that are corrupting the meters on most exercise equipment. First, people vary wildly in size, shape, and condition. Second, people can do things that make exercise easier. For example, they can hold onto the rails on a ste machine and cut the number of calories burned in half. Third, manufacturers seem to be overly optimistic because it makes their customers feel good. Add this all together and you can get
some really bad calorie estimates. Be sure to check out our new video podcast, Stuff from the Future. Join how Stuff Work staff as we explore the most promising and perplexing possibilities of tomorrow the house Stuff Works. I Find app has a arry down at it today on iTunes