I'm not looking to poke the troll nest, but I do have to ask...why in this day and age are we still so fixated on the concept of "winning?" I will freely admit I rarely watch sports, and truth be told, it's because I find little interesting about them. If I do, I prefer something like gymnastics, or ice skating...something with artistic content - just so I'm clear about my own preferences. That said, sports in general are a relic of a time when it was necessary for human survival to be the fastest, the strongest; when you needed to keep your troops in the mindset to fight at a moment's notice. We are not in that time anymore.
So why the overarching focus on "winning?" If you love the sport, as
@Perados mentioned above, no one can take that from you. If are good at a sport, no one can take
that from you. Do you only do it to win? Will you stop if you do not feel you are "the best" or do not get the accolades you think you should have? If not, than what difference does it make who you play against?
As we are finally realizing that human life may not be as binary (simplistic) as we previously believed, I think that many of our convenient divisions, sports and gender separation being but one, will become artifacts. We have a strange, and uncomfortable relationship within and without of ourselves - we are social, but want to be independent; we are inclusive but want to be exclusive; we want to be welcoming, but are inherently xenophobic (according to sociologists - I question this strongly); we want to fit in, but want to stand out. You get the idea. We are a mass of contradictions - and all of them seem to be binary. Is it any wonder that there is backlash against the very idea that we are not binary at all?
And so my dodge of the entire question. Don't make sports a competitive contest. Do it for the love of it. Do it to keep in shape. Do it for the freedom of physical expression. Marvel at the beautiful bodies and what they can do when they are trained, or naturally if that is the reason (Michael Phelps has a natural genetic aberration that makes him uniquely gifted as a swimmer - should he be banned from the sport because of that? I don't know of one other swimmer would think to suggest such a thing.) But stop this ultimately fruitless, transient pursuit of being the "winner." It carries over into the rest our lives - as evidenced by the atrocious behavior of our president, a man who is so egocentric, egotistical, so adverse to showing anything he feels resembles "weakness"; so consumed with "winning," he uses it to justify anything. It's gotta stop, doesn't it?
And if not, then let's have lots of different leagues. Those that compete without the aid of chemical enhancement. Then you have the Juice League - athletes that will voluntarily turn themselves into the fantastical gladiators with the aid of every chemical known to science. Then transgender league, and on and on. Does that seem like a better scenario? I doubt it.
We've got to, somehow, realize that 'transgender, 'bisexual,' 'black,' 'white,' 'Muslim,' 'gay,' 'straight,' 'Christian' and all the rest - all these labels ultimately do is divide. We can't survive that way. We are people. We are human.