The fin is designed for the perfect execution of the tempo, therefore it increases the stretching of the ankle in the sole direction. For beginners, this can cause leg or foot cramps. In such a case, take off your fins, carefully stretch your feet and toes into a ticking position with your hands, then shake them off and swim 100-200 meters without fins in breaststroke, or perhaps do a few angles at the bottom of the pool while diving under the water. Gradually get your feet used to the fin, take it off every 400 meters and include relaxing swims without fins.
