I've done a couple 30 day stints in county - you are going to experience close to this...
it won't be like what you see on tv. The first 72 hours you'll be unlock down. 2 guys to a cell and only 1/2 hour out of the cell into a common area a day. You won't be able to do any exercise there outside of pushups. More than likely you'll bunk with someone coming down from some drug.
Then you'll be in general pop. but it's not like prison where you have free roam. I was locked into a dorm which roomed 32 mates. Only 1 hour outside ever other day. Other than pacing back and forth in the dorm you won't be able to work your legs. pushups and such are the only option there as well.
Basically you won't be able to run at all while in jail as even during your "exercise" time every other day you aren't allowed to run, only walk.
And don't worry about all these "bubba" remarks. You won't be raped. No one will fight unless they already know each other from the outside. Jail is not prison. People are doing their month and getting out, or waiting to be sent to prison. Just don't be stupid and piss people off, keep to yourself and don't ask questions you shouldn't. Oh, respect the guards. One wrong look and you'll get thrown into solitary. They don't put up with jokers and such.
chances are you'll get out with muscles in atrophete (sp?).