These Mad Wave Swim Fins have been engineered to improve your leg muscle strength which in-turn improves your swimming speed and performance over long and short distance swimming The short blade of the Mad Wave Swim Fins promotes a shorter, faster kick which closely mimics that of which you will perform in a swimming competition allowing you to practice at your own pace whilst the the swim fin enforces a correct body alignment and feet positioning Without swim fins you will find your muscles will get overworked and therefore you will be unable to maintain a fast pace for a long period of time, by wearing short blade fins like these you will be able to kick faster and for longer than ever before which will not only improve your leg strength but it will also improve your cardiovascular strength giving you long-term performance gains This fin can be used by all levels of swimming to boost cardiovascular conditioning and accelerate speed during workouts. Features:Build Leg StrengthTrain your legs muscles for increase speed speed and endurance Short BladePromotes shorter and faster kicks which closely mimic those you will use in swimming competitions Closed Heel DesignCreates a comfortable and secure fit which inhibits hyper-flexion(tearing or deformation of posterior ligaments) Blade AngleThe Short Fin blade aligns with the natural angle of the foot, promoting a proper kick Ankle FlexibilityIncreases flexibility and range of motion for a more free and efficient swim kick 100% Natural RubberLong lasting and durable Great for All Skill LevelsAppropriate for fitness and competitive swimmers