Running is not for me: knees are pretty much shot.
The weight room is not for me: too much testosterone there.
I swim like the proverbial brick (and there's no pool near me anyway), so swimming is out.

That only leaves bodyweight exercises. So, I am youtubing my way though a self-assembled "beginning gymnastics" programme. So far all I really only know is that force multipliers can make even the slightest frame into a VERY substantial mass to be moved through space.

Oh, that and a single pull-up _properly done_ is not as easy to achieve as one might think.