"One is born with either XX or XY chromosomes"

"sports contestants entering a competition as a woman, but with all the musculature and strength of a man"

Now, coincidentally, I was half-listening/half-sleeping to a radio show on just this subject the other night/morning, forcussing on several 'female' athletes who had had rather traumatic experiences in this regard, and about how the Olympics, in particular, has dealt with the issue over the decades. These were women who, they said, had never had reason to question their sex until they won a major race (they were all runners), and complaints were lodged. Then some eggheads were weighing in on the biology of it, and what I gathered was that, in females, the chromosomal situation is not always so black-and-white. And then I was back in the house I grew up in, and I was supposed to be running a marathon, but I couldn't find my running shoes, and I crawled into that little cubby-hole under the stairs ... and ... I don't remember after that ... but I woke up in a cold sweat ....