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, ...

In this challenge, contenders take on a contortionist’s hardest stretches.

Gymnastics requires incredible core strength — try these strategies from an NCAA champ and an Olympian to take your ab workouts to the next level.