Explosive Kick Drills: Boosting Leg Strength in Butterfly

The butterfly stroke demands not just rhythm and coordination, but serious leg power. The signature dolphin kick — a powerful, wave-like motion initiated from the core and hips — is the heartbeat of butterfly swimming. For swimmers looking to improve propulsion, speed, and endurance, developing explosive kick strength is non-negotiable.

In this article, we’ll dive into the most effective explosive kick drills that target the muscle groups essential for a strong butterfly kick and explain how to incorporate them into your training for optimal performance.

🧠 Why Explosive Kicking Matters in Butterfly

While the arms provide propulsion, the legs stabilize the stroke and drive forward motion. A strong, fast dolphin kick can:

• Improve start and turn speed

• Enhance underwater breakout distance

• Maintain rhythm and body position

• Reduce reliance on upper-body fatigue

Without power from the legs, butterfly falls apart quickly — especially in longer distances.

🦵 Key Muscles Used in Butterfly Kick

• Core muscles – for body undulation and stability

• Hip flexors and glutes – drive kick initiation

• Hamstrings and quads – control knee movement

• Calves and ankles – provide finishing snap and propulsion

Building explosiveness in these areas will translate into sharper, more efficient kicks.

🏊‍♂️ Explosive Kick Drills for Butterfly

🔹 1. Vertical Dolphin Kick Drill

Purpose: Builds leg and core power, especially in deep water.

How to Do It:

• In deep water, perform fast dolphin kicks in a vertical position.

• Arms can be by your side, crossed over your chest, or above your head for difficulty.

• Kick for 20–30 seconds per rep with controlled rest.

✅ Targets hip and core-driven kick motion.

🔹 2. Sprint Kick Sets with Fins

Purpose: Adds resistance and speed to kick sets, increasing leg engagement.

How to Do It:

• Use short fins and perform sprint 25s focusing on dolphin kick.

• Mix underwater dolphin kicks off the wall with surface sprints.

Sample Set:6×25 dolphin kick sprint (with fins), 20 sec rest

✅ Builds fast-twitch muscle and kick tempo.

🔹 3. Resistance Band Kick-Offs

Purpose: Strengthens push and explosive kick from a wall or block.

How to Do It:

• Anchor a resistance band behind you.

• Push off in streamline and perform a short burst of dolphin kicks against resistance.

• Release the band to experience a speed burst after resistance.

✅ Simulates race-like power and resistance training.

🔹 4. Underwater Butterfly Kick Max-Distance

Purpose: Develops leg drive and lung capacity post-start and turn.

How to Do It:

• Push off in streamline and kick underwater as far as possible without surfacing.

• Focus on strong, consistent kicks.

• Repeat with gradually increasing distance goals.

✅ Reinforces explosive distance-per-kick.

🔹 5. Kickboard Butterfly Kick Sets

Purpose: Isolates kick mechanics and strengthens legs through repetition.

How to Do It:

• Hold a kickboard out front and kick only with dolphin motion.

• Focus on keeping hips high and generating movement from the core.

• Add interval sprints for intensity.

Sample Set:4×50 kickboard butterfly kick @ high effort

✅ Improves endurance and kick rhythm under load.

🧠 Tips for Effective Explosive Kick Training

• ✅ Engage your core — don’t rely on knee flicking

• ✅ Focus on tight, fast kicks, not large, splashy movements

• ✅ Use proper foot positioning — pointed toes with loose ankles

• ✅ Alternate intensity days with technique-focused sets

• ✅ Stretch hips and ankles regularly to improve kick range

🏋️‍♂️ Dryland Exercises for Butterfly Kick Power

Combine in-pool drills with strength training to maximize gains.

Key Movements:

• Jump squats – train explosive lower-body strength

• Plank pulses and hip raises – build undulation control

• Resistance band dolphin kicks – mimic in-water motion

• Ankle mobility drills – increase kick efficiency

🔁 Sample Explosive Kick Set (Intermediate Swimmer)

Warm-Up:

2x100 freestyle easy

4x25 dolphin kick (streamline on back)

Main Set:

4x25 vertical kick (arms above head), 20 sec rest

4x25 kickboard butterfly sprint, 30 sec rest

4x25 underwater dolphin max distance

4x25 resistance-band dolphin kick push-offs

Cool Down:

100 backstroke, easy flutter kick

🏁 Final Thoughts

A powerful butterfly kick starts with explosive leg training and focused technique work. By combining water-based drills with dryland strength exercises, you can transform your butterfly into a stroke that’s not only rhythmic and fluid — but also fast and powerful.