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The Strokes Simplified V- Butterfly

As with all strokes, great butterfly is the result of the same principles for fast swimming- increased propulsion, reduced resistance, and great rhythm. The major components of successful butterfly include-

  1. Establish a strong catch and propulsive arm action.

  2. Use the momentum of the recovering limbs and the timing of the first kick to facilitate synchronization of the stroke rhythm.

  3. Optimize undulation to facilitate arm actions while minimizing increases in drag

  4. Appropriately time the leg and arm actions within the stroke cycle.

These five components all interact to some extent and any problems with timing will influence the execution of any action. There are a lot of other aspects of the stroke that can be considered; however, these aspects are usually errors that are preventing swimmers from accomplishing the critical tasks above. Other aspects of technique can be important, but only in the context of the effect each action has on the four priorities listed above. If a movement is not negatively affecting the main priorities, it’s best left alone.

Strong Catch and Propulsive Arm Action

As with the other strokes, butterfly pull is characterized by extension in front followed by a bending of the elbow and shoulder rotation to achieve a vertical forearm and open arm pit. Once this position has been achieved the shoulder is adducted and extended to complete a direct pulling action.

As a generality, differences in the catch position and timing can exist between 50/100m and 100/200m butterfly swimmers. These differences are explored below.


For those butterflyers specializing in the 50m and 100m events, the catch is initiated almost immediately upon entry and there is minimal lateral movement on the arms in the front of the stroke. Once the catch is initiated, the pull is directly backward. This faster, more direct catch minimizes any hesitation in the front of the stroke and allows for a deeper, more immediate direct application of force, both of which allow for higher speeds to be obtained. However, the greater force requirements limit sustainability of this style of butterfly.


100/200m butterflyers typically enter the water wider and then slide the hands outside the shoulders. This action allows the head and chest to sink deeper in the water, which will be explored below. From this wider position, the swimmer pulls straight back and as the arm pits close, the hands will move inward toward the waist. As the wider, shallower pull requires less force than the deeper, narrower option, it is more conducive to individuals racing over 200m.


At the very extreme, some 50m freestylers have demonstrated success in the 50m event. These individuals exhibit a very direct, straight arm pulling action. As this action is quite powerful, it necessarily requires the ability to produce very high levels of force. These forces levels are also quite difficult to sustain, as indicated by the inability of these swimmers to compete successfully past 50m. Flaurent Manaudou, Roland Schoeman, and Cesar Cielo demonstrate this style of butterfly swimming. All were world champions over 50m in both butterfly and freestyle, as well as international medalists in the 100m freestyle, yet never competed over 100m butterfly.

Use the Recovering Arms and the First Kick to Facilitate Synchronization of the Stroke Rhythm

One of the critical actions of butterfly is coupling the momentum of the arm recovery, the first kick, and the undulation of the torso. At the front of the stroke, it is important for the swimmer to get the body back into streamline, achieve full extension of the arms, and set up the torso to create leverage on the water with hips higher than the chest.

The forward momentum of the arms can be used to swing the arms to full extension. The rotational momentum of the arms will help to depress the chest to set up the pull. Finally, the kick can help to lift the hips as well. If all of these actions are timed appropriately, the swimmer can achieve all of the required positions with minimal effort and little chance of error.

This is particularly important in the sprint events as there can be no wasted action to ensure that stroke frequency remains high. If this coupling is executed correctly, all of the prerequisites for an effective stroke cycle are set up for the start. The sprinter can time it up and go. Excellent timing is the hallmark of beautiful butterfly and it all starts at the beginning of each stroke cycle.

For 200m focused swimmers, there is more room for error. With slower stroke rates, there is slightly more time to set up each action in the front of the stroke, and the coupling action can be less precise.

A final, more speculative benefit of this action is related to added mass, or the water that is pulled along with the body during phases of acceleration, such as during the pull. At the same time, when the body suddenly slows, this water rushes forward which can accelerate the swimmer.

In front of the stroke following entry, there is a lack of propulsion and corresponding slowing of the body. At this time, the added mass of water continues to accelerate the swimmer forward. It is critical to be in a streamlined position to fully take advantage of this effect. Velocity profiles of butterflyers indicate an acceleration at the beginning of the stroke cycle that is otherwise unexplained by the propulsion created by the kick.

Optimize Undulation to Facilitate Arm Actions While Minimizing Increases in Drag

Effective undulation is critical to help swimmers navigate the challenge of bilaterally recovering the arms without rotation while operating within the constraints of human anatomy. Not only does undulation allow for humans to work around mobility restrictions, it aids in the conservation of momentum so that the arms can recovered ballistically rather than muscularly.

In addition, effective undulation can help swimmers generate the power required to swim effective butterfly. As described above, by slightly depressing the chest prior to pulling, swimmers can then leverage up over the pull to generate power. The provides a mechanical advantage for the muscles responsible for propulsion. A flat trajectory of the torso during the pull will impair the application of force.

Undulation is tightly coupled with the magnitude of breathing action as the body will follow the head. High, slow breathing will magnify the amount of undulation and increase drag. As what goes up, comes down, a high breath can also lead to driving the head deeper when re-entering the water.

The downside of undulation is that it moves the body out of streamline, increasing the drag experienced by the swimmer. More undulation is not necessarily better. In general, there is a move toward a tighter, flatter, and snappier interpretation of the body undulation, particularly in the short events. The swimmer must learn how to maximize the benefits of undulation to create propulsion and allow for effective recoveries, while also minimizing the impact of drag due to excessive undulation.


Sprint butterflyers demonstrate a much flatter, tighter undulation below. This tighter, flatter undulation allows for higher stroke frequencies and the advantages of the undulation while minimizing drag. It also supports the faster, more direct catch in the front of the stroke.


While the same principles are followed for 200m swimmers, these individuals tend to exhibit a greater degree of undulation. As the 200m distance requires significantly greater levels of endurance, greater undulation allows the swimmer to maximize the efficiency of force application and arm recovery. As stroke rates tend to be slower, there is more time for these actions to occur.

The most obvious difference is the greater depression of head and chest in the front of the stroke. This action coincides with the lateral shift of the arm prior to the initiation of the catch. This lateral action gives the swimmer time to let the chest and head drop.

What’s important to remember is that regardless of the degree of undulation, swimmers must return to a streamlined position in between stroke cycles.

Appropriately Time the Leg and Arm Actions Within the Stroke Cycle

As the sport has progressed, the majority of successful 200m butterflyers have exhibited a strong, consistent kicking action throughout the entire 200m distance. This includes a strong kick in both the front of the stroke and the back of the stroke cycle. While there are exceptions, this kicking rhythm is exhibited by the majority of current champions.

As described above, the undulation of the body is critical for optimal arm actions. It is the torque created by the kicking action that helps to facilitate this undulation by elevating the hips. It then becomes critical to optimally time the arm and leg actions to conserve momentum. If these movements are out of sync, rhythm and efficiency will be impaired.

The simplest way to focus on the timing of the kick is to couple the first kick with the entry of the arms and the second kick with the exit of the arms. As described above, kicking upon entry helps to extend the body forward and place the hips in a streamlined position. This position also facilitates the initiation of the pull.

By kicking as the hands exit, the hips and torso will be elevated in the water, which also serves to level out the torso. Both of these actions will allow for the existing momentum of the arms to carry the arms through the recovery. Otherwise, the arms would have to be lifted out of the water, slowing stroke rate and greater accelerating fatigue.

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