Body Wave and Undulation Drills for Better Butterfly

Unlock the Power of the Wave — Mastering the Core-Driven Motion That Makes Butterfly Fly 

Butterfly is often described as the most beautiful stroke in swimming — but also the most misunderstood. Many swimmers treat it as an arm-powered stroke, flailing their arms and kicking wildly from the knees, only to tire out by the 50-meter mark. The truth? Butterfly isn’t about arms or legs — it’s about the body wave. 

The real power of butterfly comes not from muscle strength, but from a smooth, rhythmic, full-body undulation — a wave that begins in the chest, travels through the hips, and ends in the toes. This wave is what propels you forward with grace, efficiency, and power. And when you master it, butterfly stops being a struggle — and becomes a glide.

In this guide, we’ll break down the science of the butterfly wave, and deliver the most effective body wave and undulation drills to transform your stroke — from beginner to elite.

🌊 Why the Wave Is the Heart of Butterfly

Unlike other strokes, butterfly relies on sequential body movement — not isolated limb action.

The Ideal Butterfly Wave Sequence:

1. Chest presses down → hips rise

2. Hips rise → knees bend slightly

3. Knees bend → feet snap together in a powerful whip

4. Feet snap → body rises to surface for breath

5. Head returns → chest lowers again to restart the wave 

💡 This isn’t two separate movements — it’s one continuous, fluid motion. Like a dolphin cutting through water.  

When done correctly:

• You generate propulsion from your core, not your arms

• Your hips stay high — reducing drag

• Your kick becomes powerful, not chaotic

• Your breath happens naturally — not as a struggle

🛠️ 5 Essential Undulation Drills for Butterfly Mastery

1. Streamline Dolphin Kick (Underwater) 

Purpose: Learn to initiate the wave from the chest — not the knees.

How to do it:

• Push off wall in tight streamline (arms locked behind ears, core braced, toes pointed)

• Perform 5–8 dolphin kicks underwater

• Focus:

  • Chest pushes down → hips rise

  • Knees stay soft, feet stay together

  • No big splashes — smooth, quiet motion

🎯 Cue: “Press your chest into the water — let your hips follow like a wave.”  

💡 Use fins if needed to feel the motion — remove them once rhythm is internalized.  

2. Vertical Dolphin Kick 

Purpose: Isolate core-driven undulation without forward momentum.

How to do it:

• In deep water, cross arms over chest

• Kick vertically to keep your head above water

• Keep knees underwater — only hips and chest move

• Focus on rhythm and control, not power 

🎯 Cue: “Think of your body as a slinky — the top moves first, the bottom follows.”  

✅ Advanced variation: Hold a small medicine ball between your hands to increase resistance.  

3. Surface Undulation (No Arms) 

Purpose: Feel the wave on the surface — without arm distraction.

How to do it:

• Lie on your stomach in shallow water

• Keep arms at your sides

• Perform dolphin kicks while keeping your face in the water

• Focus on the rise and fall of your chest and hips — not just your legs 

🎯 Cue: “Feel your chest sink, then rise — your hips follow like a tide.”  

💡 Pro Tip: Have a coach or friend watch from the side — your body should look like a gentle sine wave, not a bouncing jackhammer.  

4. One-Arm Butterfly with Undulation Focus 

Purpose: Isolate the wave while reducing complexity.

How to do it:

• Swim butterfly using one arm only (other arm at side or in streamline)

• Use a snorkel to remove breathing stress

• Focus only on the body wave — don’t think about the arm

• Feel the wave carry your arm through the water 

🎯 Cue: “Let the wave lift your arm — don’t pull it.”  

💡 Do 4 x 50m per arm — focus on rhythm, not speed.  

5. “Wave and Breathe” Drill (Full Stroke Integration) 

Purpose: Link the wave to breathing — the most common breakdown point.

How to do it:

• Swim full butterfly

• Breathe only when your chest rises naturally — don’t lift your head

• As your chest rises, your head lifts slightly to inhale

• As your chest lowers, your head submerges — exhale steadily 

🎯 Cue: “Breathe with your chest — not your neck.”💡 Use a Tempo Trainer to lock in rhythm — 1.6–1.8s per cycle for 100m pace  

📈 How to Measure Your Undulation Progress    

Underwater Distance	Measure glide after 5 dolphin kicks	10–15m per wall (SCY)
Body Line	Film side view — is your body in a smooth S-curve?	No sharp angles, no hips sinking
Stroke Count	Count strokes per 25m	Should stay consistent or decrease as wave improves
Perceived Effort	Rate 1–10 — does the same speed feel easier?	Lower score = better wave efficiency

⚠️ Common Mistakes — And How to Fix Them     

Kicking from knees	Creates drag, wastes energy	Cue: “Initiate from your sternum — not your kneecaps”
Lifting head too high	Drops hips, breaks wave	Cue: “Breathe forward — not up — like a dolphin”
No chest movement	Wave starts at hips — ineffective	Drill: Vertical kick + “Press your chest down”
Rushing the wave	Breaks rhythm, causes fatigue	Use Tempo Trainer — slow it down
Arms pulling before wave	Disrupts timing	Practice one-arm drill — let wave lead

📅 Sample Undulation Workout (45 Minutes)

Warm-Up:

• 400m easy choice

• 4 x 50m flutter kick + 4 x 50m backstroke 

Undulation Focus:

• 6 x 15m Streamline Dolphin Kick — 30s rest

• 6 x 30s Vertical Dolphin Kick — 30s rest

• 4 x 25m Surface Undulation (no arms) — 20s rest

• 4 x 50m One-Arm Butterfly (snorkel) — 45s rest 

Integration:

• 4 x 50m Full Butterfly — focus on wave rhythm

• Use Tempo Trainer: 1.7s per cycle 

Cool-Down:

• 200m easy backstroke

• 5 min thoracic spine mobility (cat-cow, foam roll) 

Final Thoughts

Butterfly isn’t about strength — it’s about rhythm. It’s not about flailing — it’s about flow. It’s not about power — it’s about wave.

When you master the body wave, butterfly stops being a battle and becomes a dance — a powerful, graceful, and deeply satisfying motion that carries you effortlessly through the water.

So stop thinking about your arms.Stop thinking about your legs.

Start thinking about your chest. 

Let it lead.Let it rise.Let it carry you.

Press. Rise. Snap. Glide. 

Because in butterfly, the fastest swimmers don’t swim with their limbs — they swim with their wave. 🦋💙