Tight Calves

[Catrin]

That makes a lot of sense- thanks for the explanation! I imagine that it's a good core workout as well. I'll definitely try this!

There is another one, though it isn't really about the hip flexors - it is about taking the legs out of the crunch equation. I've been told that my legs are so strong that in any of the normal crunches my abs don't get much of a chance to actually do anything. This requires a yoga block and a stick (a broom stick would work if nothing else).

Put yoga block between knees and draw knees up towards the chest in a crunch position. Take the stick with both hands and try to touch feet with stick - apparently with the knees separated and in this position the legs cannot "help" the core out.