How to Improve Your Dolphin Kick and Swim Faster
/
Your Fastest Fly
in 14 Days!
At the beginning of my coaching career, I was mystified by a phenomenon in the pool: certain swimmers seemed to effortlessly glide underwater with remarkable dolphin speed, leaving their competition in their wake. What was their secret? They had mastered what many consider swimming’s most powerful weapon: the dolphin kick.
Over the years, I’ve seen this one skill consistently separate average swimmers from elite performers. Time and time again, athletes who focused on refining their underwater dolphin kick made dramatic gains - not just in technique, but in actual race results. Whether shaving seconds off their personal bests or finally breaking through to podium finishes, the common denominator was always the same: a powerful, efficient, and well-trained dolphin kick.
What Is a Dolphin Kick?
Video - Vertical Dolphin Kick exercise
The dolphin kick technique mimics the powerful, undulating movement of a dolphin through water. By generating a coordinated, wave-like motion that initiates in your core and ripples through your body to your toes, you create a propulsive force that can significantly increase your speed underwater.
While the dolphin kick is the foundation of butterfly swimming, its applications extend far beyond this single stroke. The underwater dolphin kick has become a critical component of competitive swimming across all strokes, particularly during the underwater phases following starts and turns—those crucial moments where races are increasingly won and lost.
Michael Phelps, arguably the greatest swimmer of all time, revolutionized the sport partly through his extraordinary underwater dolphin kick. His ability to maintain incredible dolphin speed in water while underwater gave him a competitive edge that helped secure his record-breaking Olympic medal haul.
However, mastering the dolphin kick isn't easy. It demands a perfect blend of core strength, flexibility, and technical precision. Many swimmers struggle to perform efficient dolphin kicks, significantly limiting their potential in the water. The good news? With dedicated practice and the right approach, this skill is entirely learnable.
Start at the Core: The True Power Source of Your Dolphin Kick
Through years of coaching experience, I've discovered that the strength and effectiveness of the dolphin kick originates from the core—not the legs, as many incorrectly assume. Think of your body as a whip, with the movement initiating at your belly button and rippling outward through your hips, knees, ankles, and finally your toes, creating a powerful downward AND upward force.
Many swimmers make the mistake of prioritizing arm technique while neglecting the underwater phases of their races. But once they commit to core-focused training- even just 10 minutes a day of targeted exercises like planks, hollow holds, reverse crunches, and leg lifts - the results are often dramatic.
Quick Tips for Enhancing Core Engagement in Your Dolphin Kick:
Integrate daily core exercises: Focus on movements that target the complete core, including planks, hollow holds, and leg lifts.
Practice dolphin kicks on your back: This position naturally emphasizes core engagement and helps you feel the proper movement pattern.
Visualize the kinetic chain: During practice, actively visualize the movement initiating from your core, not your legs. This mental cue can dramatically improve coordination.
Incorporate medicine ball work: Exercises like medicine ball slams and throws help develop the explosive core power needed for effective dolphin kicks.
Unleash Your Dolphin Speed Through Enhanced Flexibility
One of the most overlooked aspects of mastering the dolphin kick is flexibility—especially ankle mobility. Limited range of motion in the ankles can place a hard cap on your potential for speed underwater, regardless of how strong your core is.
A well-structured flexibility routine can make a dramatic difference in the effectiveness of your dolphin kick. Key elements to include:
Soft Tissue Work foam roller, trigger point ball drills targeting the calves, soleus, and feet
Mobility exercises that dynamically target and stretch the ankle joint and supporting muscles
Fins are used during technique drills to progressively encourage swim-specific range of motion
Streamlining and Dolphin kicks executed with conscious focus on maximizing toe point
With consistent practice, these simple habits can significantly improve ankle mobility, increase propulsion during your kick, and extend the distance you travel off each wall—all of which directly impact your overall swim performance.
Refining Your Technique: The Art of the Underwater Dolphin Kick
Understanding the biomechanics of an effective dolphin kick is crucial. Each kick consists of two distinct phases: a powerful downward stroke AND an upward kick that generates propulsion.
Many swimmers make the mistake of not applying equal force to both the downward and upward phases. Fins in the water, hip extension, and glute exercises in the gym can enhance feel for the lift phase of the kick.
The ideal dolphin kick maintains a relatively narrow amplitude, approximately 120-155 degrees of knee flexion. Kicks that are too shallow generate insufficient propulsion, while excessively large kicks create unnecessary drag that negates their propulsive benefit.
Avoiding Common Dolphin Kick Mistakes
Through thousands of hours watching swimmers attempt to master the dolphin kick, I've identified several common pitfalls that limit effectiveness:
1. Excessive Knee Bend
Problem: Over-bending the knees creates a "bicycling" motion rather than a fluid undulation.
Solution: Focus on initiating movement from your hips, not your knees. Practice with a kickboard held between your knees to force proper hip engagement.
2. Rigid Ankles
Problem: Stiff ankles prevent the final "snap" that completes the propulsive phase.
Solution: Incorporate daily ankle flexibility exercises and train periodically with fins to reinforce the correct range of motion.
3. Disconnected Core Movement
Problem: Failing to engage the core results in isolated leg movement without the crucial undulating body wave.
Solution: Practice vertical dolphin kicks in deep water with arms crossed over chest, focusing on initiating movement from the core.
Personal Coaching Insight
One of my most memorable coaching experiences involved working with Alex, a highly competitive age-group swimmer who excelled in virtually every aspect of swimming except underwater dolphin kicks. Despite his exceptional stroke technique and conditioning, he consistently lost ground to competitors during the underwater phases.
We implemented a comprehensive program focused exclusively on developing his dolphin kick:
Daily sessions dedicated to underwater dolphin kick drills
Core strengthening routines performed twice per week.
Video analysis comparing his technique to elite swimmers
5-10 minutes of ankle and hip flexibility protocols
Guided visualization exercises to reinforce proper movement patterns
In many cases, swimmers have shaved seconds off their race times in just one season—largely due to improvements in their underwater phases. These experiences continue to reinforce my belief: mastering the dolphin kick can be a true game-changer in competitive swimming.
Integrating Effective Dolphin Kick Drills Into Your Training Regimen
To systematically develop your dolphin kick, incorporate these proven drills into your regular training:
1. Vertical Dolphin Kicks
Maintain a vertical position in deep water with hands crossed over your chest, using dolphin kicks to stay afloat. This drill forces proper core engagement and removes the assistance of horizontal buoyancy. Advanced swimmers can hold weights above the water for added resistance.
2. Progressive Underwater Distance Sets
Set specific goals to travel certain distances underwater using dolphin kicks. For example:
4 x 25m with the first 10m underwater dolphin kick
4 x 25m with the first 12.5m underwater dolphin kick
4 x 25m with the first 15m underwater dolphin kick
Gradually increase either distance or decrease time as you improve.
3. Resistance Training
Practice dolphin kicks using resistance tools such as:
Parachutes
Drag socks
Resistance bands are attached to the wall. This strengthens the specific muscle groups needed for powerful dolphin kicks while reinforcing proper technique under load.
4. Dolphin Kick on Side
Practice dolphin kicks while positioned on your side, with one arm extended. This variation helps develop propulsion in various positions and improves body awareness during the kick.
5. Single-Arm Butterfly Swimming
Perform butterfly with one arm extended forward while the other executes the stroke cycle. This drill highlights body undulation and forces greater reliance on the dolphin kick for propulsion.
What Muscles Do Butterfly Kicks Work?
Understanding the muscular engagement in the dolphin kick can help you target your strength training more effectively. The primary muscles involved include:
Core muscles: Rectus abdominis, transverse abdominis, and obliques initiate the movement and coordinate the body wave.
Hip flexors: These muscles drive the downward phase of the kick.
Glutes and lower back: The erector spinae and gluteal muscles power the upward phase.
Quadriceps and hamstrings: These large muscle groups help transfer force through the knees.
Calves: These complete the propulsive "snap" at the end of each kick.
Targeted strength training for these muscle groups—particularly abs exercises—can significantly enhance your dolphin kick power and endurance.
Ready to Master Your Dolphin Kick?
Developing an efficient, powerful dolphin kick isn't just about swimming faster—it's about swimming smarter. In today's competitive swimming landscape, underwater dolphin phases have become increasingly decisive factors in race outcomes.
The journey to mastering the dolphin kick requires patience, consistent practice, and attention to technical details. But the rewards—significant time improvements, reduced energy expenditure, and a beautiful, fluid swimming style—make it well worth the effort.
Which aspect of dolphin kick development will you focus on first? The core-driven body undulation? Ankle flexibility? Or perhaps integrating some of the specialized dolphin kick drills into your training regimen?
Share your experiences and questions in the comments below—I'm passionate about helping swimmers at all levels unlock their potential through mastering the dolphin kick