Strict Muscle Up age limitations

Yesterday I witnessed a 74 year-old man doing 5 strict muscle ups (narrow). And he wasn't even a small guy. But I guess he had done them for pretty much all his life as he is a retired gymnastics coach.

 

Then I looked the exercise up in Coach's book and was pretty surprised it only had a difficulty rating of 2/5.

 

I wonder, will there be a point where someone will not be able to achieve a muscle up? Could I even get my 60 year-old dad to do one?

Depends on prior training, lifestyle, etc. One of Coach's students is/was 70 years old and can do an iron cross.

I think FritsMB was 70 when he started training the muscle up, and he was pretty successful with it.