A lot of classes (circuits etc) and dvds I have seem to feature 'mountain climbers', quite often as a cardio element of an at home workout.
I don't have a problem with doing a cardio interval but my body just seems to have a weird thing with mountain climbers! I can do them but only very slow (by comparison to some of the super speedy ones I've seen performed!) and my hips seem to get almost 'stuck' when I'm moving my legs back and forth. I have to sort of twist weirdly to get my legs to do it and my hips click awkwardly. Is it a flexibility issue? I used to be a gymnast a looooong time ago and I've never had any previous flexibility issues.
Or is it just me? Can I improve this? Is my body just fundamentally not designed for this kind of motion?