Funny, since you wrote your reply as part of the quote like if it was my writing, in doing a reply it comes out empty.
You refer to "coed", so I guess you are from USA.
I was part of the group managing a sport society long ago in my country of origin, and what you are saying is not so true for everybody and everywhere.
If they are still in school, typical for gymnasts (due to the requirements of flexibility, many gymnasts where adolescents or maximum in the early twenties), they will do extra activities training, preparing for competition and then doing the competitions, but they will still have to attend school like anybody else, in countries where there is a minimum legal level of studies (typically, linked to age). They may have period of more intense training when closer to the qualification, but does not mean they will not have to frequent school, and it does not mean they will be in a monastery.
It is widely known that in USA in some sports (e.g. American football, or football for you), sport results may bring to leniency on the academic side, and professional football (soccer, for you) players do not have forcibly studies, but again, given the age of many gymnasts, they would nonetheless attend normal school, which if public is in general mixed.
Former Eastern Europe had special facilities where it may have been different, and I know Qatar opened some school where they boast about their athletics preparation, and in the Qatar one I doubt there are mixed sexes school (but I think also it is at university level, so different age).
It is true that Zorlun has put Myriam has being Texan, but still, I don't recall any indication that all of the USA olympics athletes where monks and nuns
from when they started preparing to qualify for the Olympics