Learning Swimming

Recently I took some swimming lessons in the gym I used to go. I’ve learned breaststroke before but I can’t swim fast with it. My flexibility is bad so I can’t do the right gesture and the rotation of leg may increase my risks of injury. I know if I get some advice from a professional coach and to some training my helps but the easiest way is to change my stoke. So I try to learn crawl swimming these days. And it’s much more tired than breaststroke especially when I wore the flippers. I got my calf cramped and still under recovery.