Fins are fun. Put them on and you instantly become fish-like. Now, having a killer freestyle kick is not as desirable for a triathlete as it is for a swim sprinter. Triathletes need to preserve their lower body for the bike and run. However, having a poor kick will render your legs a liability during the swim, so your kick is important to maintaining a correct body position and balance.
Here are a few good reasons to incorporate fins into your workouts.
Practice a Good Kick Motion
An effective freestyle kick starts at the hip, then bends at the knee, followed by the foot. It’s often described as a “whip” kick. The “up-kick” is done with a straight leg. Wearing fins helps the swimmer adopt this motion.
Help Ankle Flexibility
Another important piece of the kick is ankle flexibility. The swimmer should kick down with the top of their foot and up with their sole. Many swimmers find it hard to gain forward momentum with their kick and, often, this is due to their ankles not being extended.
Discovering the Water
So much of swimming is about sensations. It’s good to experiment with different speeds; different techniques; different body positions; different strokes. (What you talkin’ ’bout, Willis…?) Most equipment lets you do “discover” the water. Fins let you feel new things that you might not have felt before. Things can start clicking….
BUT…There is a danger in overusing fins. If you use your fins too much, you will miss out on the finding the best unassisted stroke for you….and that’s what you’re going to need on race day. Don’t use fins so much that you start depending on them.
As Sheila Taormina says in her excellent book, Swim Speed Secrets:
Using fins as a crutch is the worst thing a swimmer can do, and I see the used in this manner frequently. New swimmers who should be learning to feel the water will oftentimes put on fins )or be told to put them on by a coach who does not understand the importance of holding the water with one’s own limbs to generate propulsive forces) as a way to gain confidence. This slows the learning process, because every moment you are using fins means that you have lost that moment for developing true feel.