I have a desk job, so I found that I needed to let the air out of my innertube. I was a distance runner (on track scholarship) in college, but then after a permanent injury, I quit for good (or so I thought). After a few years, and 50# more, I decided to start working out again. I just moved in Feb, and my new house is exactly one mile from the Rec Center. I run there, lift weights, and run home every weekday morning. I've lost most of the innertube, but my weight hasn't gone down. I guess that is due to the air leaving the innertube, and inflating my chest...