Breaststroke has a reputation as the gentle stroke, the one people swim to take it easy. Then the lower back starts to complain, and it feels like a betrayal. I swam the 200 individual medley for sixteen years, which means breaststroke was part of nearly every training day of my career, and I can tell you the stroke itself is not the problem. The way most people swim it is. One note before we start: I am a swimmer, not a doctor or physical therapist, and the claims below are linked to their sources. Anyone with diagnosed back trouble should get individual guidance.
Why does breaststroke cause lower back pain?
Because the stroke cycles the lumbar spine through repeated extension, and poor technique turns that natural undulation into a hyperextension habit repeated hundreds of times per session. A 2024 narrative review of lower back injuries in competitive swimmers describes how the undulating motion of breaststroke and butterfly demands repetitive flexion and extension of the spine, and identifies hyperextension as a common injury mechanism, with lumbar strain, facet joint pain, and spondylolysis among the typical results. The concern is old and well documented: a case series of adolescent elite swimmers with spondylolysis, a stress fracture of the vertebral arch, tied the injury to repeated hyperextension, and most of those swimmers were breaststroke or butterfly specialists. The dose makes the poison here. A body position that arches a little too much on one length is nothing. The same arch repeated through 2,000 meters of breaststroke, week after week, is how a back gets ground down.
Is swimming breaststroke bad for your back?
No, but if your back already hurts, breaststroke is the stroke most likely to provoke it. A 2026 randomized crossover study had 30 adults with chronic low back pain swim 100 meters each of freestyle, breaststroke, and backstroke, and found backstroke was the least painful stroke during and immediately after swimming, with breaststroke at the other end. That is useful, practical information: on days when your back is irritated, swim backstroke or easy freestyle and let breaststroke wait. For that freestyle volume, keep the effort honest and aerobic. My free swim pace calculator turns a simple time trial into training paces so easy days stay actually easy.
Which technique mistakes overload your lower back in breaststroke?
Four habits do most of the damage, and they feed each other.
Driving the breath from the chin. Lifting the head and chest high to breathe by cranking the neck and arching the lower back hinges the whole movement at the lumbar spine. The breath in breaststroke should come from the body rising as the arms sweep in, with the head staying in line with the spine, eyes down and slightly forward, not from throwing the chin at the sky.
Skipping the glide. Breaststroke has a moment where the body returns to a flat, extended line after the kick. Swimmers in a hurry start the next pull before the line ever flattens, so the spine stays in some degree of extension through the entire cycle and never gets its rest position back. No glide, no neutral spine.
A kick that whips downward. When the finish of the kick drives the feet down instead of squeezing straight back, the hips pop up and the lower back arches to compensate. The kick should feel like pressing water backward with the soles of the feet, finishing in a tight streamline behind you.
A core that never shows up. The abdominal wall and glutes are what keep the undulation shallow and controlled. Without that tension, the wave of the stroke happens wherever the body bends most easily, which is the lumbar spine. This is one of the clearest cases for land training I know, and I covered what that work looks like in how much dryland training a swimmer actually needs.
How do you fix your breaststroke timing?
Restore the sequence: pull, breathe, kick, glide, with the glide getting a full beat of its own. The cue I like is to kick your hands forward: the moment the legs snap back, the arms should already be shooting into the extended line, so the kick's power launches you into a flat, stretched glide. If your pull and kick happen at nearly the same time, you get a short, bobbing stroke that never flattens, and your back pays for every cycle. Swim a few lengths counting one full second of glide on each stroke. It will feel slow. It is usually faster, because the glide is where breaststroke actually travels.
Which drills take pressure off your back?
Three that I have swum thousands of times, in this order.
1. Two kicks, one pull
Swim breaststroke taking two full kicks for every arm pull, holding the streamlined glide between them with eyes down. The extra kick forces you to spend time flat and extended, which is exactly the position a hyperextended stroke never visits.
2. Eyes-down breaststroke
Swim normal breaststroke, but keep your eyes on the water in front of you instead of the far wall as you breathe, letting the shoulders rise only as much as the insweep lifts them. The cue is to surf forward over the water, not climb upward out of it.
3. Kick with a board, hips high
Breaststroke kick with a kickboard, focusing on keeping the hips near the surface and finishing every kick straight back. If your hips sink and your back arches to hold the board up, shorten the set. Quality over meters, always.
When should you see a professional about back pain?
When pain persists for more than a couple of weeks, wakes you at night, radiates down a leg, or keeps returning every time you swim breaststroke despite technique changes. Those are signs to see a doctor or physical therapist rather than push through, and this matters double for teenagers training seriously, since the spondylolysis research above was done in adolescent swimmers. Fixing your stroke is the right move for a cranky back. Diagnosing one that stays cranky is a professional's job. For the bigger picture of what swimming does for joints over a lifetime, I wrote is swimming good for your joints as you age.
The frustrating part of all four mistakes above is that none of them can be felt from inside the stroke. Head position and body line are exactly what SwimRead measures from a short phone video, frame by frame, entirely on your device. Join the beta and see what your stroke is doing to your spine before your spine tells you.