How Swimmers Train Their Underwater Dolphin Kick

Watch a top level swimming final closely and you will notice something. Some of the most important moments happen where the cameras struggle to follow, under the water after every start and turn. The underwater dolphin kick has become one of the biggest weapons in modern swimming.

Rules allow swimmers to stay underwater for up to 15 meters after the start and each turn in freestyle, backstroke and butterfly. Swimmers with a powerful kick use that distance to build speed before they ever take a stroke. Here is how athletes train it.

Start With a Perfect Streamline

Speed under the water begins with shape. Swimmers press their arms tightly over their head, stack one hand on top of the other and squeeze their ears between their arms. The head stays neutral, looking down, not forward.

A tight streamline reduces drag, which is the resistance of the water pushing back. Even a strong kick loses its value if the body is loose and wide. Coaches often have swimmers push off the wall and glide without kicking at all, just to feel how far a clean shape can carry them.

Kick From the Core, Not Just the Feet

A common mistake is to kick only from the knees. Strong underwater swimmers start the motion in the chest and core and let it travel down through the hips to the feet, like a wave moving down a rope.

The kick has two parts. The downbeat drives the feet down and creates most of the forward push. The upbeat brings the legs back up and, in skilled swimmers, also adds speed. Training both directions, not just the downward snap, makes the kick more balanced and more efficient.

Ankle flexibility helps too. Pointed toes act like a fin. Many swimmers stretch their ankles regularly to improve that range.

Bigger is not always better. A huge, slow kick creates more drag. Many fast swimmers use a smaller, quicker kick that keeps the body moving at a steady speed. Coaches watch for a tempo the athlete can hold without the body bobbing up and down.

Drills That Build the Kick

Athletes build the skill with focused drills:

Vertical kicking. Swimmers kick in deep water with their arms crossed or in streamline above their head, keeping their head above the surface. It builds power and shows quickly whether the kick is even in both directions.

Kicking on your side. Doing dolphin kick on each side helps swimmers feel the upbeat and the downbeat equally.

Kicking on your back. Back dolphin kick with a tight streamline builds core strength and is a key skill for backstrokers.

Fins. Short training fins let swimmers feel a fast, connected rhythm and build leg strength. Coaches usually mix fin work with sets done without them.

Distance targets. Swimmers push off and count kicks to a set mark, aiming to cover the distance with fewer kicks or in less time.

Breath Control and Dry Land Strength

Staying underwater longer requires calm and fitness, but it must be trained carefully. Swimmers build gradually, always with a coach or lifeguard watching, and never practice holding their breath alone. Repeated breath holding without supervision can cause a swimmer to black out with no warning, which is extremely dangerous.

Good programs build underwater distance step by step and focus on efficiency, so swimmers get more speed for each breath rather than simply holding on longer.

Dry land training supports the kick. Core work such as planks and hollow body holds, hip mobility exercises and leg strength training all help swimmers produce a stronger, smoother wave through the body.

The Payoff

A strong underwater kick can turn a close race. Over several walls, a few tenths gained each time adds up to a clear lead. That is why the best swimmers treat the underwater phase as its own stroke and train it every week.

For young swimmers, the lesson is simple: master the streamline, kick from the core and practice safely. The water hides this skill from most viewers, but the clock always shows it. Follow Legend Magazine for more on how athletes train and compete.