How Does is work?

This might not be a good topic for everyone but there is something that I would really like to know/understand. Also, I write this while fully knowing that I could very probably come across as very shallow and vain.

Anyway, here goes:

I go to the gym after work every day, it ,very conveniently, is right next door to my office. Also, if I decide not to go I have to walk past it and will more than likely feel very guilty knowing that I really should be in there. But that's not what I want to write about.

Belgium has a very big muslim community and we have all types/kinds here. So what I can't understand is this, there are a couple of muslim ladies who come to my gym. They wear full muslim gear out in the street but when they come in to the gym and change into sweats like all of us. How is it ok for them to dress like that? (I have no problem with it, I was just wondering how it's ok according to their beliefs), it's just that it's not a ladies only gym it's a mixed gym. How is it ok for them to uncover their heads in the gym but no where else?

If I "had" to wear traditional clothes like them every day I would so not be in the gym either. I mean if nobody is going to see you or your figure for that matter what does it matter if you are not 100% toned or even 80 % for that matter. I go to the gym to try and look good, ok, reasonable in the type of clothes I like, but really if I wore a bag all day every day I don't see the point in going to the gym every day.

Therefor, if any of you have any ideas about this, don't be shy, tell me what you think