His new profession would be dance instructor.
For a few years when I was around age 10 I took ballet and tap dance lessons at a small private studio which was owned and taught by a retired Rockette. I still remember her beautiful long legs which always wore fishnet stockings.
At some point your friend will need to more or less gradually reduce his level of physical exertion or he will injure himself.
Such is the life of dancers.
Wendy