In training, I really struggle with front/back crawl or fly kick exercises.
Not only do I not get much propulsion but the little I do get pretty much drains all my energy and leaves me gasping for breath.
My question is: if you have also struggled with this at some point, ie. you are a competent swimmer but the vast majority of your ability comes from upper-body strength, what exercises and quantity of those exercises (in or out of water) did you use to improve?