How to Improve Underwater Kicks for Faster Swims

The fastest part of many races happens before a swimmer takes their first stroke. Learning how to improve underwater kicks can turn a solid start or turn into real momentum, helping young swimmers carry speed farther down the pool without working harder.

Underwater kicking is not about holding your breath as long as possible or taking the biggest kicks possible. It is about building a tight bodyline, creating a smooth wave through the body, and knowing exactly when to surface. For developing swimmers, this skill takes patience, mobility, and consistent coaching. The goal is efficient speed, not simply more distance underwater.

Why underwater kicks matter in racing

After a start or turn, the swimmer is moving at their highest speed. Water resistance increases quickly once strokes begin, so a strong underwater phase lets a swimmer preserve more of that speed before transitioning into their stroke.

In freestyle, backstroke, and butterfly, the dolphin kick is a major performance skill. In breaststroke, the underwater pullout follows different rules and requires its own technical sequence. Young athletes do not need to chase elite-level distances right away. They need to develop a reliable, legal underwater that helps them leave every wall with control and confidence.

A swimmer who takes one clean, powerful underwater line off every turn will often gain more than a swimmer who tries to force six ineffective kicks. Quality comes first. Distance and speed follow.

Start with a better streamline

A great underwater kick cannot overcome a loose streamline. Before focusing on the legs, make sure the swimmer can leave the wall in a position that lets water move smoothly around their body.

Hands should be stacked tightly, with one hand placed over the other and thumbs locked around the lower hand. The arms press behind the ears, the head stays neutral, and the eyes look straight down or slightly forward depending on stroke and body position. The ribs should stay connected, the core engaged, and the legs squeezed together.

The most common issue is a swimmer who looks up, bends at the hips, or lets their arms separate as soon as they push off. Those small gaps create drag immediately. Ask swimmers to imagine they are a pencil traveling through the water: long, narrow, and firm.

Use the wall correctly

A powerful push-off gives the underwater kick something to work with. Feet should plant securely on the wall, knees should be bent enough to create force, and the swimmer should drive straight out rather than upward toward the surface.

For younger swimmers, start with a simple challenge: push off in a tight streamline and glide until the speed begins to fade. This teaches them to feel the value of position before adding movement. If the streamline falls apart during the glide, fix that first.

Build the dolphin kick from the core

The dolphin kick is not a knee kick. It begins from the chest and hips, then travels down the legs like a controlled wave. The knees bend naturally, but they should not lead the movement.

A useful cue is: press the chest slightly, snap the hips, then let the feet finish the kick. The downbeat creates most of the propulsion, while the upward motion should remain connected and controlled. Ankles need to stay loose so the feet can act like fins.

Swimmers often make one of two mistakes. Some keep their bodies too stiff and kick only from the knees, which creates drag and little forward movement. Others overdo the wave, bending too much through the hips and losing their line. The best kick is compact, rhythmic, and connected from the torso through the toes.

For many young swimmers, kicking with fins can help them feel this pattern. Fins provide feedback and help athletes recognize whether the kick is traveling through the body. They are a teaching tool, though, not a replacement for technique. A swimmer should still be able to maintain a clean kick without them.

Improve ankle mobility and foot position

Flexible ankles are a performance advantage in underwater kicking. When the toes point naturally and the ankle can move freely, the foot holds more water and produces a stronger finish. Stiff ankles can make even a well-timed kick feel flat.

Dryland mobility should be gentle and consistent. Pointing and flexing the feet, controlled ankle circles, calf stretching, and sitting with the tops of the feet extended can all support better range of motion. Young swimmers should never force painful positions. Mobility develops over time, especially when paired with regular kicking practice in the pool.

In the water, remind swimmers to finish each kick through their toes. Feet that are flexed or separated create resistance. Think of the legs as one connected tail, with the feet finishing every wave together.

Practice the right drills

Drills work best when swimmers know what they are trying to feel. A long set of underwater kicking without attention to bodyline can reinforce poor habits. Keep repetitions short, give a clear focus, and allow enough rest for quality.

Here are five productive options for a structured practice:

• Streamline glide to breakout: Push off, hold a tight line, take two to four controlled dolphin kicks, then begin the stroke. Focus on staying narrow through the transition.

• Vertical dolphin kick: Kick in deep water with arms crossed at the chest or held overhead. This reveals whether the movement comes from the hips or only the knees.

• Back dolphin kick in streamline: Kicking on the back helps swimmers feel hip-driven movement and maintain a neutral head position.

• Underwater kick count: Travel a set distance with a limited number of strong kicks. This encourages swimmers to create distance per kick instead of rushing.

• Breakout timing repeats: Practice the final underwater kick and first stroke together. The swimmer should not pause, lift the head, or lose speed before surfacing.

For beginner swimmers, even two or three well-executed kicks off a wall are a major step forward. More experienced athletes can use timed 10-yard or 15-yard efforts, but speed should never come at the cost of a legal, controlled breakout.

Time the breakout, not just the kick

A fast underwater phase ends with a fast breakout. If a swimmer stays underwater until they slow down, their first stroke will feel heavy. If they surface too early, they may miss valuable speed from the push-off.

The right timing depends on the swimmer, the stroke, and the race distance. A 50-yard sprint may call for a more aggressive underwater than a 500-yard freestyle, where oxygen management matters more. Backstroke athletes may carry speed longer underwater, while a developing freestyler may benefit from a shorter, more dependable sequence.

Teach swimmers to surface while they are still moving quickly. The final dolphin kick should help bring the body toward the surface, and the first stroke should connect immediately. There should be no glide at the surface with the head lifting to search for air.

Keep it legal and safe

Competitive rules limit how far swimmers may travel underwater after starts and turns. In most freestyle, backstroke, and butterfly events, swimmers must break the surface by the 15-meter mark. Breaststroke has specific pullout rules that swimmers need to learn carefully with a coach.

Safety matters just as much as speed. Underwater work should be supervised, especially for young swimmers. Never make breath-holding contests part of practice, and do not encourage athletes to hyperventilate before underwater repeats. Coaches and families should reinforce that a swimmer can stop, surface, and reset whenever needed.

Make underwater kicking part of every practice

The fastest improvement comes when underwaters are trained regularly, not saved for occasional sprint sets. A swimmer can build the habit during warm-up, turns work, kick sets, and race-pace sets. Small, focused repetitions add up quickly.

Parents can support the process by valuing technical progress, not only race times. Ask your swimmer what cue they are working on: tighter streamline, softer ankles, stronger hip movement, or a cleaner breakout. This keeps the conversation focused on skill development and gives young athletes a clear purpose at practice.

At Alpha Swim Club, technique is treated as a foundation for long-term progression. A swimmer who learns to leave each wall with discipline will carry that confidence into every stroke, every race, and every new level of training.

The next time your swimmer pushes off the wall, challenge them to make the water quieter. A tight line, a connected kick, and a confident breakout can make a powerful difference before the race even feels like it has begun.