I made a vow to be more adventurous this year, so I’m signing up for all the weird and wonderful workouts I can find in my hometown of London, then reporting back on what I’ve learned about fitness, ...

When you think of contortionists, images of circus performers (perhaps a la Cirque du Soleil) likely come to mind. The bending, twisting, and stretching seem impossible — and never fail to mesmerize.

The art of contortion creates nearly impossible feats with the human body where toes wiggle next to ears and backs become like bendy straws, but contortionists like Jared Rydelek (pictured here) say ...