This post is courtesy of Abbie Fish of RITTER Sports Performance. From qualifying for the Olympic Trials to working at USA Swimming’s headquarters, Abbie has been on all sides of swimming. Abbie is a stroke mechanics guru and believes anyone with the heart to train can benefit from technical advice! [CLICK HERE] for a FREE stroke technique lesson from Coach Abbie!

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For anyone who has ever been coached with Butterfly—the word undulation should not be new. Undulating means (literally) move like a smooth, wave-like motion. Within our short-axis strokes, undulating is a key component to a faster time. Basically, undulating aids our forward motion in the pool by strengthening our pull (putting us in a stronger physical position to catch water)  AND  by firing our hips and lower  back  MORE  to create a greater amount of propulsion from our kicks!

Basically – if you do not undulate in fly, you won’t be able to pull or kick as much water! 

 A3 Performance On Deck blog

To have a successful undulation motion during your fly stroke–there are few important concepts:

  • A Strong Core.

The undulating motion starts at the core and ripples through the body like a wave. Without a strong core to create the motion itself—it will all fall apart and your body alignment will suffer.

  • What Goes up--Must Come Down!

When teaching kids how to swim fly (especially younger swimmers)--they have a tendency to use their undulation to drive themselves up and down, versus forward.

Remember: the goal is to get down the lane as fast as possible—not dive down towards the bottom of the pool.

  • Body Alignment is Key!

While swimming fly–if you lead the undulation with your head and not your chest—your body will come out of alignment. This misalignment will create a bigger increase in frontal drag (i.e. more resistance) against your forward motion.


Be sure to stay tuned for our next post—where we will discuss the pulling pattern of fly, along with timing issues, and the entire fly sequence!

Until Next Time, 

A. Fish


Learn more from A3 Performance Partners Abbie Fish and Ritter Sports Performance on Social Media:

Fly Series Pt. I: Dont Dive Down Fly Forward! @AB Fish & @Ritter Sports Performance
Fly Series Pt. I: Dont Dive Down Fly Forward!  @afish1 & @rittersp
Fly Series Pt. I: Dont Dive Down Fly Forward!  @theafish1 & @rittersp
Fly Series Pt. I: Dont Dive Down Fly Forward! Fly Series Pt. I: Dont Dive Down Fly Forward! Fly Series Pt. I: Dont Dive Down Fly Forward!
December 26, 2017 — A3 Performance

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