Ask a swimmer to show you their breaststroke kick and most of them will show you their knees. The knees come forward under the chest, the thighs swing down like a sail, and the feet arrive late and half turned in. They feel effort, see no speed, and conclude they need stronger legs. They almost never do. They need the heels to go somewhere else.
Breaststroke is the third leg of the 200 individual medley, the event I swam at two Olympic Games for Brazil and won at the 2015 Pan American Games in Toronto in 1:57.06. It is the one stroke where the legs, not the arms, decide the race, and the whole kick is built on two things: where the heels go, and where the feet point when they get there.
Why does the breaststroke kick matter more than the other kicks?
Because in breaststroke the legs are the main engine, not a stabiliser. The US Masters Swimming breaststroke kick guide states it plainly: "Your kick contributes significantly more propulsion in breaststroke than it does in backstroke, butterfly, or freestyle."
It is also the odd one out mechanically. The same page notes that "Breaststroke kick is the only kick in which your feet turn out rather than in." In the other strokes you press with the tops of your feet; here the pressure sits on "the insides of your feet, the bottoms of your feet, and even your shins." A good flutter kick carries over almost nothing here. It is a different skill.
Where should the heels go on the recovery?
Up to the hips, with the knees staying where they are. That cue fixes more breaststroke kicks than anything else I say on a pool deck, and the kick guide puts the same mechanic in muscular terms: "Your hamstrings power your kick recovery, bringing your feet to your hips." The kicking drills page in the same guide gives the back-kick instruction as "To recover your feet, avoid moving your knees forward. Instead, focus on bringing your heels to your hips."
Heels to the hips keeps the thighs in line with the body, so the recovery costs you almost nothing. Knees forward drags the thighs down and under, and now you pull a wall of water toward your chest every stroke. The faster swimmer is usually not the one kicking harder. It is the one whose recovery is cheap.
Why do the feet have to turn out before the kick starts?
Because turned-out feet are the only surface you have to press with. The guide says "your feet need to be pointed out to the side as much as possible after coming up to your hips," and sets the target in its list of mistakes: "Ideally, your toes will face the side of the pool."
If the toes still point backward when the legs begin to extend, your shins and soles slice through the water instead of pushing against it. You get the fatigue of a kick with none of the propulsion. The guide compresses the whole rhythm of this into six words: "Be aggressive with your recovery and patient with the set-up." Most swimmers do it backwards, drifting the heels up and then rushing the kick.
How wide should the knees be?
Wide enough that your feet can turn out, and no wider, which is a different answer for every body. The guide refuses to name a number: "As a result, there's no one perfect kick width." What it gives instead is a priority order: "The actual width of your kick is secondary to getting your feet wider than your knees," and "Your knees shouldn't move out when you kick."
The usual narrow-versus-wide argument skips what limits you. A narrow kick with properly turned-out feet demands real rotation at the hip, knee and ankle. In the study Swimming Speed of The Breaststroke Kick, Strzała and colleagues note of earlier work that "the more skilled ones had a larger external knee rotation," and the same discussion puts the practical consequence as "the easier it is to keep the kick narrow and kick back rather than out."
Force a narrow kick onto joints that will not rotate and you get the feet pointing the wrong way, which is the worst of both. Find the width where your toes can face the pool wall, then stop moving the knees.
Which direction should the kick press?
Straight back, not around in a circle. The guide calls the circular idea a misconception and gives a test you can run from your own video: watch the knees during the kick, because "If they're sliding out, you're kicking around." Stable knees mean the feet are doing the work. A kick that travels around also takes longer to finish, which caps your stroke rate.
How does the kick fit into the timing of the stroke?
It lands after the pull, not inside it. The guide is specific: "Your legs should recover right as the arms finish their recovery," and "And your arms shouldn't pull until you complete your kick." A kick arriving while the hands still pull back cancels out half your stroke. I wrote the full sequence up in breaststroke timing, and the breaststroke hub covers how the arms fit around it.
How does SwimRead read this part of your swimming?
It does not read breaststroke yet, and you should know that before you film anything. The SwimRead home page states that "The current beta supports freestyle filmed from the side of the pool," and that "Backstroke, breaststroke, butterfly, underwater footage, starts, and turns are not supported analysis modes in this beta."
What it does today is read a short freestyle clip. The page asks you to "Aim for 10 seconds of continuous freestyle," filmed "in landscape from the side, with the whole body visible, a stable camera, standard lens, and normal playback speed," and from that "On-device pose detection estimates up to 33 body landmarks in sampled video frames." It stops short of a verdict, since "These estimates are not validated technique grades."
On breaststroke you are still the analyst. Phone on the deck in landscape, film from the side, and look at one thing: do the heels come up to the hips, or do the knees come forward to the chest.
What should you drill this week?
- Kick on your back. From the drills page: "To recover your feet, avoid moving your knees forward. Instead, focus on bringing your heels to your hips."
- Kick on your back with a board on the knees. Same page: "Although it's OK to contact the board, try to avoid kicking the board up and down with your knees."
- Vertical kick. The page notes that "Vertical kick also encourages you to turn your feet out to support yourself in the water."
- Buoy between the knees. "Place a buoy between your knees and continue to kick without letting go of the buoy." Build into this one slowly; it loads the knees.
- Two kicks, one pull. "Take two additional kicks while your arms are streamlined in front of you."
- Count. "Just count your kicks and aim to improve the number over time."
Run those counts through my free swim pace calculator to see whether the quieter kick came out faster, not just easier. If the kick is clean and the stroke still stalls off the wall, the pullout is the next piece.
SwimRead is free while in beta, and paid plans will come later with beta testers told before anything changes. For a reading of your freestyle, join the beta and leave your email for an invitation as beta spots open.