What type of modern Olympian would be best suited for time travel to the middle ages?

>just look at what happened whenever an alchemist claimed to have the ability to conjure gold
Weren't they kept on retainer until the king lost patience? Just being able to produce should keep you on retainer a bit. You won't have freedom but you should get a roof and food.

It works fine. As long as you can find a patron.

Nobody's going to shit on the goose that lays the golden eggs. Although a rival might try and turn or kill you.

Some managed to produce a steady stream of fools gold, they did not fare much better, unless you count living in a dungeon till you go blind as an acceptable standard of living.

Really, the argument should have ended here; the decathlon requires the most balanced athletic skills. Assuming equal intellectual capacity of all candidates, a decathlete is the best choice. Equestrians or archers also aren't bad choices, those are useful or valuable skillsets.

I guess this is a when and were type of thing. I mean this is a large area for a thousand years. Have any sources on alchemists being left in dungeons until they go blind? I don't have any figures pointing that it wasn't the case, everyone I know about was the beginning of the Renaissance.

Possibly just an average person living in Rio, they would know their way around machetes and shovels.

This.
Fencing is meh compared to HEMA or other competitive MA groups

Moving left and right is largely useless in a one-on-one duel, because lateral movement is easily accounted for with small turns. The person can circle all the way around you, and you've basically just twisted on your heel a little.

This is what people who don't know anything about fencing believe.

I'll agree that sport fencing doesn't visually resemble "real" combat, but that's because the advancement in the sport has been so dramatic that it is literally too fast for most spectators. All the principle components of fencing still remain, but they've been refined into a sport that makes historical fencing more like play-acting than a physical competition.

It sounds like you did fencing for a year or two in something like a high school gym.

HEMA is like mall karate.

Depends on the country. In England, it would be an archer, because archery was the only legal sport for peasants and tournaments with cash prizes were common.
It doesn't matter how strong you are, if you aren't born in a village the peasants will ostracise you and blame you for (possibly imaginary) crimes, sending you off to the chopping block, so you can't farm.
And if a guild isn't backing you, you can't practice a trade.
You could try begging, but the guards would probably be suspicious of how well-fed you are and kill you as a spy.
You could try and make money at sport - but very few sports had cash prizes (archery being an exception) and most of them, e.g. jousting, melee fights, aren't practised today and are highly dangerous.
You could join the army, but knowing how to run or how to fence won't make you any less likely to get infected and die. And you aren't trained or equipped.
You don't even speak the old-fashioned dialect, and believe me, that will make it difficult to communicate. It's more than just 'thee' and 'thou'.
Your only chance is archery tournaments (if you're male, females can't compete because misogyny, so they'd have to whore themselves out.)