[hammock]

Not sure why you've been downvoted. Weightlifting (specifically heavy+low reps) has major effect to promote bone density, that's why astronauts do it now in space. It also prevents muscle atrophy, that much should be obvious. Finally, more muscle mass will keep your metabolism up and prevent fat gain.

[jfo]

I know you meant resistance training in general wrt astronauts in space but I just got the funniest image in my head of Chris Hadfield doing a zero G overhead press with a loaded bar and floating all over the place hahaha

[Out_of_Characte]

So far I've seen no rules stating that world records should be taking place on earth gravity. Maybe this is my chance to take some weightlifting records.

[michaelcampbell]

Sadly, in zero G there is no weight so every record would be 0. Equally sadly, there are no "masslifting" records to actually beat.

What does "lift" even mean where there is no objective "down"?