You didn't really elaborate on your motivation to do so, but you could always just create your own in case you mainly want to keep track of them. If you want feedback or discussions, you could periodically mention it here in the fitness community. Just a thought.

Aren't there self-hosted federated strava-like applications?

Hevy apps social side works fine for that.

Though as we are in fediverse, there's probably some security/privacy issues with it.

There are apps where you can see how others train. And not on paper in theory, but their actual workout they did in the gym. It is increadibly cool to see what people do, if you are exploring.

To piggyback onto the above comment:

https://www.twitch.tv/directory/category/fitness-and-health

You can watch actual workouts in real time and usually they have a chat command such as !currentsession that you can type in chat and it will provide a set-by-set breakdown of their current gym sessions. You can also ask questions during their stream which they will answer during their rests between sets.