I used to take flying trapeze classes at the Toronto School of Circus Arts -- it was a lot of fun, but is definitely hard. Mind you with my proportions I never looked like a graceful creature. I had to give it up because I was really rough on my shoulders, and then when that got better, I had some knee problems. It seemed I had weak glutes (muscles used when swinging), and to compensate I was using my I-T bands...and in turn they got very tight, and were pulling my kneecaps out of alignment. It took about 6 months of physio to fix that.
Having said that I would love to go back and give it another try.http://www.torontocircus.com/