Bob Bowman’s Favorite Underwater Dolphin Kick Set

Lots goes into dolphin kicking like a champ each time you disappear under the surface.

Beyond the technique challenges, which are plenty challenging on their own, there’s developing the conditioning to be able to keep kicking hard and fast when your legs are burning and your lungs are not-so-politely requesting you to surface for a breath.

Plus, dolphin kicking is straight up harder than swimming.

For example, a study (Sergovia-SanBenito et al., 2025) compared swimmers doing fast 25s underwater dolphin kicking and full-stroke swimming. The underwater reps produced roughly 50% more lactate even though there was similar oxygen saturation and perceived effort.

Which means swimmers need to train the dolphin kick like the skill that it is.

And this dolphin kick set, one of the regular UDK training tools for Bob Bowman’s elite athletes, is designed specifically to bullet-proof your underwaters.

The Bowman Dolphin Kick Set

The set is simple. Just a bunch of 25s. Doesn’t look too tough.

But Bowman is upfront about the difficulty:

“It’s one of the hardest things that we do,” he said during an ASCA presentation in 2025 when he discussed this set.

The repeated fast underwaters stresses the legs while the short bouts of easy swimming provide just enough recovery to keep the kicking quality at AAA-levels. Instead of stacking one or two fast underwaters, you’re stocking a warehouse of race-relevant reps.

• See also: 5 Sets for Improving Underwater Dolphin Kick

Bowman’s swimmers do the set in a short course yards pool while wearing fins. This is intentional and not to make the set easier—a study with swimmers (Wang et al., 2025) showed that hard kicking with fins increases theoretical power output by ~26%.

Here is the set:

2-3 rounds:

• 4×25 free swim easy on :20
• 4×25 UDK fast on :20
• 3×25 free swim easy on :20
• 3×25 UDK fast on :20
• 2×25 free swim easy on :20
• 2×25 UDK fast on :20
• 1×25 free swim easy on :20
• 1×25 UDK fast on :20

Bowman has his swimmers do the third round on :15. (They are elite for a reason.)

Why the Recovery Matters

Those intervals look intimidating for those of us not named Kós or Marchand, but it’s important to remember that these are some of the best swimmers and kickers on the planet. Bowman’s swimmers get around 10 seconds per rest at the wall before pushing off again, making it basically a 1:1 work-to-rest ratio.

That’s enough time to take several breaths, mentally reset, and attack the next repetition with gusto.

“The key element in these underwaters is that they have breathing time on the wall,” he explained.

For reasons that are hopefully obvious to swimmers and coaches (see also: Shallow Water Blackout – Do You Know What It is? You Should), underwater sets (especially at the end of a hard workout) should not be survival contests where they surface, take one harried breath, and struggle through increasingly sloppy dolphin kicks.

For younger swimmers, Bowman offers a variation to use as an on-ramp to the set:

2-3 rounds:

• 1×25 free swim on :30
• 1×12.5 UDK, 12.5 swim on :30
• 1×25 free swim on :30
• 1×25 UDK on :30

“For young kids, they [should] have full recovery,” said Bowman. “You don’t want to do it where they’re coming up, taking one breath, and then pushing off again.”

Wrapping Things Up

If you’re trying to improve your underwater dolphin kick, don’t just work on it when you’re fresh or at slow and easy speeds.

To build fast underwaters that you can rely on in competition, you need to train them in practice and need to train them hard. Especially given how much of a metabolic price tag extending your underwaters can have.

Start with a simple, high-rest version of the set. Steadily increase distance and rep volume. And kick your way to faster underwaters Bowman-style.

Happy kicking!

ABOUT THE AUTHOR

Olivier Poirier-Leroy is a former national-level swimmer, 2x Olympic Trials qualifier, and author of several books for swimmers, including The Dolphin Kick Manual: The Swimmer’s Ultimate Guide to a Fast Underwater Dolphin Kick.

The book is a beastly 240+ pages of actionable insights and research into elite dolphin kicking technique and performance. It details everything from mastering undulation to vortex recapturing to structuring a dryland program for dolphin kicking success.

The Dolphin Kick Manual combines evidence-based insights with a collection of 20 ready-to-go sets and a 6-week Action Plan to help swimmers set a course for dolphin kicking success.

Train smarter and kick faster.

👉👉👉 Learn more about The Dolphin Kick Manual