Zipper Drill: Improving Body Alignment in IM
- SG Sink Or Swim
- 4 days ago
- 4 min read
The Secret to Seamless Transitions and Streamlined Efficiency Across All Four Strokes
In the Individual Medley (IM), where milliseconds separate victory from “what if,” one often-overlooked factor decides races: body alignment. A misaligned glide off the wall, a collapsed core during breaststroke, or an unbalanced rotation in backstroke leaks speed, disrupts rhythm, and wastes energy.
Enter the Zipper Drill — a deceptively simple yet profoundly effective technique exercise designed to teach swimmers to “zip up” their body into a long, tight, hydrodynamic line from fingertips to toes — across all four strokes and every transition.
More than just a drill, the Zipper Drill is a mindset: a reminder that in IM, efficiency isn’t optional — it’s everything.
🧥 What Is the Zipper Drill?
The Zipper Drill trains swimmers to maintain full-body alignment by imagining a zipper running from their sternum down to their pelvis. With every stroke, turn, and glide, they “zip up” their core — engaging abs, tucking the pelvis, and extending through the fingertips and toes.
This creates:
A straight, narrow body line (reducing drag)
Stable rotation (in fly and back)
Powerful breakouts (off every wall)
Smooth stroke transitions (fly → back → breast → free)
“Great IM swimmers don’t just swim four strokes — they move as one aligned body through all of them.”— Chase Kalisz, Olympic 400 IM Gold Medalist
🌊 Why Body Alignment Matters in IM
Unlike single-stroke races, IM demands constant adaptation. Poor alignment in one stroke compounds into the next:
Stroke | Alignment Risk | Consequence |
Butterfly | Arched lower back, dropped hips | Weak undulation, early fatigue |
Backstroke | Flat or over-rotated body | Shoulder strain, slow kick |
Breaststroke | Head lifted, hips sinking | Drag spikes, kick loses power |
Freestyle | Crossed-over arms, sagging core | Wasted energy, poor rotation |
The Zipper Drill unifies all four strokes under one principle: stay long, stay tight, stay fast.
🛠️ How to Perform the Zipper Drill
✅ Basic Execution:
Swim any stroke (or IM order) while focusing on “zipping up” your core
Cue: “Zip from your chest to your hips — squeeze your belly button toward your spine”
Visualize: A line running through your body — no bends, no breaks
✅ Key Focus Points by Stroke:
Fly: Zip during the glide after the kick — chest down, hips high
Back: Zip during rotation — hips and shoulders move as one unit
Breast: Zip during the streamline after the kick — head neutral, toes pointed
Free: Zip during body roll — core engaged, no banana back
🎯 Universal Cue: “Long body. Tight core. Pointed toes.”
📈 3 Progressions to Master Alignment in IM
1. Zipper Glide (Wall Focus)
Push off wall in tight streamline
“Zip up” core, biceps squeeze ears, toes pointed
Glide 10–15m without moving
Do 6–8 x per stroke in IM order
💡 Purpose: Build awareness of perfect alignment off every wall
2. Single-Stroke Zipper (Stroke Isolation)
Swim 25m of each stroke with exaggerated “zip” focus:
Fly: One full stroke → long glide (zip during glide)
Back: 6-kick switch with tight core (zip during rotation)
Breast: Pull → kick → 3-second glide (zip in streamline)
Free: Catch-up drill with core engagement (zip during reach)
🎯 Purpose: Isolate alignment in each stroke’s unique demands
3. Full IM Zipper (Race Simulation)
Swim 100m or 200m IM
On every stroke, whisper “zip” during the most vulnerable phase:
Fly: After breath
Back: During recovery
Breast: In the glide
Free: At entry
Goal: Maintain consistent body line despite fatigue
💪 Purpose: Train alignment under race conditions
💪 5 Key Benefits of the Zipper Drill in IM
Benefit | Impact |
Reduces Drag | Tight alignment = 20–30% less resistance |
Improves Turn Efficiency | Streamlined push-offs = faster breakouts |
Enhances Stroke Transitions | Smooth fly-to-back and breast-to-free shifts |
Prevents Energy Leaks | No wasted motion from sagging or twisting |
Builds Core Endurance | Sustained engagement = stronger finish |
🧠 Coaching Cues That Stick
🧥 “Zip your core like you’re pulling on tight jeans.”
🪡 “Sew your body into one straight line — no loose threads.”
🧱 “Be a spear — not a noodle.”
🌊 “Long body on the glide. Tight core on the pull.”
⏱️ “Zip before you breathe. Zip after you kick.”
⚠️ Common Alignment Mistakes in IM — And How the Zipper Fixes Them
Mistake | Zipper Solution |
Sinking hips in breaststroke | “Zip” during glide — core tight, head low |
Flat backstroke after fatiguing fly | “Zip” during rotation — engage obliques |
Early arm drop in freestyle recovery | “Zip” on entry — reach long, core stable |
Weak butterfly undulation | “Zip” on chest press — connect wave to core |
Loose streamline off walls | “Zip” on push-off — biceps squeeze ears, toes pointed |
📅 Sample IM Workout Featuring the Zipper Drill
Warm-Up:
400m easy + 4 x 50m IM drills (catch-up, 6-kick switch)
Technique Focus:
4 x 25m Zipper Glide (one per stroke) — 30s rest
4 x 50m Single-Stroke Zipper — 45s rest
Main Set:
4 x 100m IM @ race pace
Focus: Whisper “zip” during vulnerable phases
Rest: 90s
Cool-Down:
200m easy backstroke + core activation (dead bugs, planks)
💬 Pro Insight from Elite IM Coaches
“I don’t watch their arms. I watch their core. If it’s zipped, the rest follows.”— Dave Salo, USC Trojan Swim
“The Zipper Drill isn’t just for beginners. My Olympic medalists do it every week — because alignment is the foundation of speed.”
Final Thoughts
In the IM, greatness isn’t found in flashy turns or powerful kicks alone. It’s found in the quiet discipline of alignment — the ability to stay long, tight, and fast through every stroke, every wall, every breath.
The Zipper Drill doesn’t just teach technique. It builds awareness. It builds consistency. It builds champions.
So the next time you push off for an IM set, don’t just swim. Zip up. Stay long. Move as one.
Because in the medley, the fastest swimmers aren’t the ones with the best strokes —they’re the ones with no leaks in their line.
Zip. Glide. Flow. Finish.
In IM, alignment isn’t a detail — it’s the difference. 💙🏊♂️
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