THE KICK

The dolphin kick consists of an up-and-down kicking motion by both legs simultaneously. The leg action is basically similar to that of the flutter kick. But because both legs move together, the hips are able to play a much more prominent role in propulsion. This characteristic makes the dolphin kick the fastest and most efficient of all kicks.

In performing the dolphin kick, spread your feet slightly and keep your ankles extended but relaxed. Foot and ankle flexibility is important in maintaining the fluid action of the kick.

The kick itself consists basically of a downbeat and an upbeat. In the downbeat, you bend your knees slightly, and your hips rise just as your knees reach their full extension. In the upbeat, you straighten your knees out. Figure 10.3 illustrates the phases of the dolphin kick.

Perhaps the most common mistake novice swimmers make in learning the dolphin kick is bending the knees excessively during the upbeat. This usually happens because of holding the feet and ankles too stiff. The result is a static action, which slows the stroke down and makes the arm stroke difficult. The solution is simple: allow your feet and ankles to relax, and go with the flow of your body.

Learning the Dolphin Kick

According to experts like Cecil Colwin, a top Canadian swim coach, the easiest way to learn the dolphin kick is to practice it using a kick board. Hold the board out in front of you, with your hands about one third of the way along its length. Keep your hands together, relaxed, with your palms facing down.

 As you begin to kick, remember not to push down on the board. Keep your shoulders low and your hips high. This position will permit your body to undulate naturally with the kick. Try to avoid excessive up-and-down movements of your shoulders and back. If you find yourself bobbing, hold your back straight and concentrate on kicking from the hips.

Once you have the kick down pat, you are ready to learn to coordinate it with the arm stroke.

Timing

In the modern butterfly, there are two dolphin kicks for each arm cycle. The timing of the kicks is critical to maintaining a streamlined body position, countering resistance, and supplying continuous propulsion—in short, to swimming an efficient fly.

The downbeat of the first kick occurs just as your arms enter the water. This causes your upper body to drop lower in the water than your hips, resulting in the characteristic undulating motion of the butterfly.

The downbeat of the second kick takes place during the final phase of the arm stroke, just as your hands are pushing back and up. Timed properly, it helps drive your shoulders out of the water for the recovery. At the same time, it allows you to raise your head to breathe (see Figure 10.4).

It seems that one of the two kicks is always larger than the other, depending on how fast you are swimming. When you sprint the butterfly, the second kick is larger than the first. But when you cruise the fly at a more leisurely pace, the first kick is the stronger.