For most swimmers (especially triathletes) the kick is typically the most undertrained and under-appreciated element of their stroke. However, the pace of your kick determines your baseline swimming speed and separates the truly fast swimmers from all of the rest.
What your kick should NOT do:
- Large kick: to keep drag to a minimum, the kick should stay within the hole opened in the water by the head and trunk while moving forward. Ideally, the kick should neither break the water surface nor move below the line of the body.
- Forcing the upbeat: In freestyle, the upbeat phase of the kick isn’t propulsive. Ideally you should relax your leg during the upbeat to save energy.
What your kick SHOULD do:
- Provide lift to reduce drag
- Stabilize the body and create balance for body rotation
- Sustain constant speed (instead of slowing and re-acceleration with each phase of the pull)
Now that we’ve covered those basic rules of kicking, improving your kick is not an overnight fix. It requires months of stretching, strength training and lots of kick sets.
In the pool:
Your coach should provide you with the right kinds of kick sets in order to improve your swim, beyond just meandering down the lane on a kick board. You need specific kick sets designed to build power and speed.
Increased ankle flexibility serves the same function as the flick of a fish’s tail to provide propulsion, and without it, even the strongest legs won’t kick fast. The extra plantar flexion of the ankle is relatively easy to get with the right dry-land exercises and stretching (see video below).