Olympic Races, A Question?

I confess to not being the most well versed in issues of  religion, any religion for that matter, but a question continually arises in my mind while watching the Olympic games. Can Muslim women race without being clad in a burqa and can they also run or jump without wearing a niqab? I am certain, since there were no Olympic games back in olden times, this question never was posed concerning Muslim women.

I notice that Turkish women are scantily dressed and running like the wind in races. Are they violating any religious law while pursuing a medal?

I do not have the answers to my questions. I am just asking.  I wonder what is the answer to my query?