Many people will look at this and think they are crazy. This stunt is not very dangerous. It does take a lot of upper body strength. I would LOVE to have done this. BTW, I have several hours in that model of sailplane. Too much fun!
Skydiver moves between gliders in mid-air! Red Bull Akte Blanix 2 - YouTube
Judy... not an instructor... just a private pilot with about 400 hours... 300 in complex aircraft.