Was heavily involved in the SCA for over 25 years. When I started my own company I had to cut back (also was a bit burned out). Still keep in touch with our old friends, but we limit ourselves to one event a year.
Gave up the dance company I founded and ran for 10 years. Didn't have time for two rehearsals and one performance a week, and I burned out a bit. It became too much hassle to keep arranging for practice space, arrange for musicians, come up new material, book performances, etc, When two of my lead dancers moved out of the area I decided to disband the company and work on other hobbies (see fencing). I am occasionally asked to run a workshop and I help other dance teachers, but I'm mostly inactive. Plan to go back to dancing for fun when I can find the time.
Fenced in high school and college. Stopped fencing for dancing. Then left dancing to return to fencing. Co-ran a salle for 8 years. Eventually my knees couldn't take the pounding and my company took my time, so I turned the teaching over to my students (who still run it.) Still work with individual students one-on-one, but I probably won't go back to it seriously.
Music. Still do some keyboard and recorder, but my right hand isn't the same since I broke it in a cycling accident.
Sculpture, especially glass blowing. No time right now, and not enough space. When I get inspired I pull out the tools and do some small wood or metal or paper or plaster piece. Plan to get an annealing kiln and bench stand and go back to glass some day. I have several sheets of steel and seasoned logs in the basement waiting for me.
For now, cycling, animee and movies are my main hobbies.