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The Four Functions Of Your Swim Kick

The function and importance of the kick are widely misunderstood.

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One of the great controversies in triathlon is the importance of the kick in swimming. Many triathletes feel it is better to rest the legs during a race, to save them for the bike and run. Others believe that kicking the right amount helps them swim faster and prepares the legs physiologically for a better bike and run.

Whichever strategy you think is best, one thing is certain: The function and importance of the kick are widely misunderstood. These are the four functions of your kick:

1. Propulsion

The legs can help you swim faster. To get any meaningful propulsion, one needs to use a six-beat kick, rather than a two-beat kick (see below).

2. Lift

The kick will keep your body straighter in the water and help lift the body closer to the surface to reduce drag.

3. Stabilizing force

Coupled with the counter-rotation of the core, the hardest kick should come toward the end of the propulsive phase of the underwater pull. This kick creates a force that helps increase the distance per stroke achieved.

4. Inertia

A six-beat kick—three times faster than the pull—helps sustain speed between arm strokes. This is a more efficient way to swim, rather than slowing down and speeding up through each stroke cycle.

Try the following exercises to improve your kick:

Increase ankle flexibility.

Stretching the ankle allows you to increase the range of motion. The snap of the foot at the end of the kick provides much of the force of the kick, and a supple ankle maximizes this power.

RELATED: How Can I Increase Ankle Flexibility for Swimming?

Kick properly in training.

Instead of “social kicking” with a board in practice, take it more seriously. Try using a mono snorkel and alignment kickboard from Finis. Not only will this put you in the correct body position for the swim, it will also enable you to practice streamlining while kicking. If you dedicate one entire practice per week just to kicking, you will do yourself a big favor.

Do dry-land leg exercises.

You can increase strength and aerobic conditioning of your legs and core through appropriate dry-land exercises.

RELATED: Video: Dry-Land Swim Exercises to Improve Swim Strength and Techniques

Two-Beat vs. Six-Beat Kick

In a two-beat kick, the right leg kicks down when the left hand enters the water and vice versa, followed by a slow lift of the leg. With a six-beat kick, the legs never stop kicking in either direction. Experiment in the pool to see what works best for you.

RELATED: How does Katie Ledecky Swim so Fast?

Gary Hall Sr. is a three-time Olympian who now directs The Race Club in Islamorada, Fla.