Here is another new exercise I've been playing around with. It definitely is a great core workout. I like it because unlike a plank, this is a core exercise with what I call a movement challenge. While no exercise is truly sport specific, this would be great for rock climbers. Looking at myself do the exercise, I think it can also be used as a bit of a diagnostic tool biomechanically. You can see what hip wants to open up and which one doesn't under a heavy load. Interesting!