Improving Your Underwater Dolphin Kick for Faster Times

29 November 2025

You’ve probably heard it a hundred times: underwater dolphin kicking is the “fifth stroke” of swimming. But here's the deal—if you want faster times, you absolutely must master this game-changing technique. Whether you're a sprinter looking to shave off milliseconds or a distance swimmer trying to stay competitive off walls, your dolphin kick can either be your secret weapon or your Achilles' heel.

Think about it. The underwater phase is the fastest part of any race when done right. So, why not make the most of it?

In this deep dive (pun intended), we’re going to break down exactly how you can improve your underwater dolphin kick to leave your competition in the bubbles.

Why The Underwater Dolphin Kick Matters

Ever notice how elite swimmers seem to explode off the wall or the dive like underwater torpedoes? That’s not by accident—they’ve nailed their dolphin kicks.

- It’s not just about flair, it’s about speed.
- The underwater dolphin kick can make up 15 meters off each wall (if done legally).
- For short course races, this can account for up to 60% of a race.

By boosting your underwater game, you're literally setting yourself apart from the pack. Seconds aren't just won on the surface—they're earned underwater.

Breaking Down the Dolphin Kick: What It Really Is

If you're picturing a dolphin propelling through the ocean, you're already on the right track.

The underwater dolphin kick is a wave-like motion that starts from your core and flows through your hips, knees, and ankles. It's not a knee-thrashing flutter or a rigid leg movement—it's fluid, continuous, and powerful.

Imagine a whip. The energy starts from the handle and travels down to the tip. That’s exactly how your body should move during a solid dolphin kick, starting at the core and whipping through the legs.

Common Mistakes Swimmers Make (And How to Fix Them)

Before we get into drills and workouts, let’s fix some of the most common dolphin kick screw-ups:

1. Overusing the Knees

Problem: You look like you're riding a bicycle underwater.

Fix: Focus on engaging your hips and core. Your knees should bend naturally, not forcefully. Think small, fast waves, not big clunky ones.

2. Stiff Ankles

Problem: You’re basically kicking with bricks instead of fins.

Fix: Work on ankle flexibility. Do daily stretches like toe points and shin rolls. Loose ankles = faster kicks.

3. Too Much Splash

Problem: If your kick breaks the surface, you’re not staying streamlined.

Fix: Stay tight and low during your dolphin kicks. Streamline like a missile and keep everything underwater unless you’re surfacing.

4. Holding Breath Too Long or Too Short

Problem: Oxygen is fuel. Mismanaging your breathing affects rhythm and power.

Fix: Practice controlled breath-hold sets and gradually build tolerance. Push yourself, but listen to your body.

Drills to Sharpen Your Dolphin Kick

Want to power up your kick? Here are some killer drills that’ll help you level up:

1. Vertical Dolphin Kicks

- Get in deep water.
- Hold a streamline position with your arms above your head.
- Kick vertically, going small and fast.
- Try 20-30 second intervals.

Why it works: It forces you to engage your core and improve kick tempo.

2. Kick with Fins

Use short fins to enhance your power and feel for the water.

- Do 25s underwater dolphin kick with fins.
- Focus on rhythm, not brute force.

Why it works: Fins exaggerate your motion and help you feel the correct movement pattern.

3. Wall Push-Off Kicks

- Push off the wall and dolphin kick underwater.
- Time how far you can go before surfacing.
- Stay in a tight streamline.

Why it works: Reinforces start and turn transitions while improving your lung capacity.

4. Belly, Back, and Side Kicks

- Do dolphin kicks in all positions.
- Belly = standard.
- Back = engage back muscles.
- Side = improve balance and symmetry.

Why it works: Builds all-around control and spatial awareness.

Core Strength: The Engine of Your Dolphin Kick

Let’s talk muscles. The real power behind your dolphin kick doesn’t come from your legs—it comes from your core.

Your abs, obliques, and lower back muscles are what drive that whip-like motion from your torso to your toes.

Try These Core Exercises:

- Plank Variations (front, side, reverse)
- Russian Twists
- V-Ups
- Superman Holds
- Flutter Kicks on Land

Strong core = strong kick. Simple as that.

Ankle Flexibility: The Secret Sauce

Here’s the bit that often gets ignored: your ankles.

Without good ankle flexibility, your kicks will feel like dragging anchors. You need to turn those cinder blocks into flippers.

Stretches to Add Daily:

- Toe Points with Resistance Band
- Ankle Rolls
- Wall Stretches (pressing top of foot against wall)
- Calf Raises and Drops

Commit to 10 minutes a day. Over time, your ankles will loosen up, giving you that dolphin tail effect in the water.

Breath Control: Train Yourself to Stay Down Longer

Your dolphin kick only works if you can stay underwater long enough to use it. Enter: breath control.

Here’s how to improve your oxygen efficiency:
- Do kicks to the 15-meter mark every wall.
- Add underwater kicks after every 50 or 100.
- Practice hypoxic sets (e.g., breathing every 5 or 7 strokes).

Caution: Know your limits. Don’t black out trying to be a hero.

Body Positioning and Streamlining

Think of a rocket. It doesn’t zoom through the atmosphere with arms flying everywhere. Neither should you.

Perfect streamlining minimizes drag and boosts your kick speed. Tuck your chin, stack your arms, and squeeze your ears with your biceps.

Want extra credit? Engage your glutes and keep a straight spine. A tight body slices through water like a hot knife through butter.

Training Sets to Boost Your Underwater Game

Here’s a sample session you can plug into your weekly routine:

Warm-Up:

- 300 swim (choice)
- 4x50 kick on back (dolphin) with focus on hip drive

Main Set:

- 8x25 underwater kick (streamline) @:40
- 4x50 dolphin kick with fins (25 underwater / 25 swim) @1:00
- 6x25 vertical kick :20 work / :10 rest

Cool Down:

- 200 easy swim
- 3x100 backstroke or freestyle with dolphin off all walls (no breath for first 5 strokes)

Mental Game: Pushing Through Discomfort

Let’s be real. Dolphin kicking hurts. Your lungs burn, your legs scream, and your head says, “Just breathe!”

But guess what? That’s where the magic happens.

It’s about mental reps just as much as physical ones. Teach your mind to embrace the suck. The more often you push through, the easier it gets next time.

What the Pros Do Differently

Watch any race with Caeleb Dressel or Katinka Hosszú. You’ll notice they don’t just kick hard—they kick smart.

They:
- Stay longer underwater without losing speed.
- Keep a perfect streamline.
- Know exactly when to surface (timing is everything).
- Have lightning-fast kick tempo without looking frantic.

You don’t need to be a gold medalist to do what they’re doing—you just need to practice with purpose.

Final Thoughts: Build It, Then Push It

Improving your underwater dolphin kick isn’t something that happens overnight. It’s a craft you build with reps, focus, and consistency.

But here’s the beauty of it: once it clicks, it transforms your whole swim game. You’ll explode off every wall, you’ll inch ahead of your lane mates, and your confidence? Through the roof.

So next time you dive in, give your dolphin kick the attention it deserves. Because what happens underwater sets you up for everything that comes after.