One foot to go

I was working out yesterday afternoon in the workout room at the apartment complex and there was another person in there, a male person to be exact. He was working out on the elliptical machine I usually use, so I decided to use the one right next to him. The way the machines are situated is interesting - there are two elliptical machines right next to each other, two bikes next to each other and two treadmills...you guessed it, right next to each other. Each of these machines are approximately 1-2 feet apart - pretty close if you ask me. Now, I have been a member of a gym before and the machines are all pretty close, except the closeness of the machines in the complex workout room are oddly close since they are all located in a pretty small room. Anyway, here's my question - why is it ok to be that incredibly close to someone you don't know when you are working out? I mean seriously, I would NEVER get that close to a guy (other than my husband) for a prolonged period of time - but some how it's ok because we are working out. Which, to tell you the truth, is kind of gross considering you're all sweaty and stuff. But my question is, why is it socially acceptable to be that close to someone when you are working out? Don't people who set up workout rooms aware of social norms? If you're not going to get that close when you are in a social situation, why be that close when you are working out? Ewwww, gross!!!