How can swimmers improve their butterfly technique?

Butterfly is often the most technically demanding stroke; improving it reduces energy cost, lowers race times, and decreases shoulder injury risk. Coaches and researchers emphasize that progress depends less on brute power and more on coordinated timing, streamlined body position, and targeted strength and mobility work. James E. Counsilman of Indiana University stressed rhythm and undulation as foundations of efficient butterfly, a principle that remains central to modern coaching.

Body position and undulation
Efficient butterfly begins with a horizontal, slightly nose-down alignment and a rhythmic dolphin motion generated from the hips and core rather than exaggerated arm-driven undulation. The downkick should be timed to assist the early part of the arm pull so propulsion from legs and arms stacks rather than fights. Hand entry is most effective when narrow and fingertips-first, reducing drag and preserving shoulder health during recovery. Coaches at USA Swimming recommend keeping the recovery relaxed with high elbows and a controlled acceleration into the next catch to preserve momentum and prevent wasted energy.

Timing and breathing
Timing links the kick, catch, and recovery. Most elite swimmers use two kicks per arm cycle: a smaller kick as the hands enter and a stronger downkick through the catch and finish. Breath timing is brief—lifting the head just enough to inhale during recovery—so the core can immediately re-establish a streamlined line. World Aquatics technical guidance for competitive stroke mechanics highlights the importance of minimizing head lift to reduce resistance and preserve rhythm through the turn and underwater phases.

Drills, strength, and practice structure
Targeted drills isolate the elements that produce efficient movement. Single-arm butterfly builds a stable catch and rhythm while reducing bilateral strain. Body-dolphin drills emphasize hip-driven motion and help internalize the undulation. Vertical kicking with arms at the side strengthens the core and ankle plantarflexion critical for effective dolphin kicks during starts and turns. Swimming Australia’s coaching materials prioritize underwater dolphin-kick training as a means to extend speed off the wall and conserve energy during races.

Dryland and injury prevention
Strength training should prioritize core, lats, glutes, hip flexors, and scapular stabilizers. Rotator cuff and scapular-control work reduce the chronic impingement that causes swimmer’s shoulder; USA Swimming and national sports medicine programs recommend progressive load and mobility routines rather than high-volume, high-load pressing that can exacerbate shoulder problems. Flexibility of the thoracic spine and shoulders supports a full, comfortable recovery and better hand entry angles.

Cultural and environmental considerations
Regional training cultures affect emphasis: some Australian programs favor extensive underwater work and high-intensity intervals, while many American club coaches focus on drill progression and biomechanical efficiency. Swimmers training at altitude or in colder water may need adjusted warm-ups and progressive exposure to avoid early fatigue or stiffness. For masters swimmers and those with anatomical differences, prioritizing tempo, reduced range, and creative drill selection preserves performance while lowering injury risk.

Improving butterfly is a gradual, evidence-informed process of correcting timing, reinforcing hip-driven undulation, and supporting the body with appropriate strength and mobility work. The combined effect is greater speed with less energy and a lower long-term injury burden.