How to Swim Butterfly: Build It From the Dolphin Kick

Butterfly is a kicking stroke with an arm recovery attached. Learn the dolphin kick until you can cross a pool with it on your front, your back and your side. Then learn the timing: two kicks per arm cycle, one as the hands enter, one as they exit. Only then add the arms. Adults almost always attempt the arms first, exhaust themselves in ten metres, and conclude they are not strong enough. Strength was never the problem. Timing was.

And a note before you start. If your shoulder hurts in freestyle, do not learn butterfly. Fix the shoulder first.

Step One: The Dolphin Kick

The wave starts at the chest, not the feet. Press your sternum gently down, let the movement travel through the hips, and let the legs follow like the end of a whip. The feet stay together. The knees bend, but only as a result of the wave passing through, never as the driver of it.

Practise it three ways, a length of each: on your front with your arms extended, on your back with your arms at your sides, and on your side with one arm extended. The side kick is the one that teaches you where the power lives.

Spend a month here. Genuinely. There is no version of butterfly available to someone whose dolphin kick does not move them.

Step Two: The Two-Kick Timing

One arm cycle, two kicks.

1. Kick one as the hands enter the water in front of you. This kick drives the hips up and sets the body line.
2. The pull — hands sweep out, in towards the navel, then back past the hips.
3. Kick two as the hands exit at the thighs. This kick launches the recovery.
4. Recovery — arms sweep low and wide over the surface, relaxed, little fingers up.

The first kick is the one everybody forgets, and forgetting it is why the front half of the stroke sinks.

Drill it as single-arm butterfly: one arm doing the stroke, the other extended in front, full dolphin timing underneath. Twelve lengths of that will teach you more than a hundred lengths of thrashing.

Step Three: Breathing

Breathe low and forward, chin skimming the surface, as the arms sweep past the hips. Do not lift the head. The instant the chin rises, the hips drop, and you are swimming uphill.

Breathe every second stroke while you are learning. Breathing every stroke is fine too and is what most adults end up doing. Nobody sensible breathes every third.

The face goes back into the water before the arms come round. Head down, then hands past.

The Order Matters

Never swim butterfly tired. It is the one stroke where fatigue produces technique so bad it is genuinely worth stopping mid-length.

Common Mistakes

• Learning the arms first. The universal error. Butterfly is built from the kick.
• Only one kick per cycle. The entry kick is the one that vanishes, and the front of your stroke sinks with it.
• Lifting the head to breathe. Chin skims. Hips stay up.
• Kicking from the knees. The wave starts at the chest.
• A high, straight-arm recovery. Low, wide and relaxed. High recoveries wreck shoulders.
• Swimming lengths of it. Three to six strokes, then rest. Distance comes last, if ever.
• Swimming it with a sore shoulder. Do not. See a physiotherapist.

Safety

Butterfly is the hardest stroke on the shoulders and the lower back. Overuse injuries build quietly and then arrive all at once.

Keep the recovery low and relaxed. Stop at the first twinge and see a physiotherapist rather than swimming through it. If your lower back aches after butterfly, your hips are dropping — that is a technique fault, not a core-strength one, and adding sit-ups will not fix it.

Never practise underwater dolphin kick as breath-holding work. Prolonged or repeated breath-holding, particularly after hyperventilating, causes shallow-water blackout: a silent, warningless loss of consciousness that has drowned strong swimmers in supervised pools. Surface and breathe. It is never a contest.

Swim with a lifeguard on duty. Butterfly is exhausting and fatigue arrives faster than you expect.

Should You Learn It At All?

Honestly, for most adult swimmers, butterfly is optional. It will not make you fitter than freestyle, it will not make you faster, and it carries the highest injury cost of the four strokes.

What it will do is teach you body undulation, timing and rhythm, and it makes every other stroke feel easy afterwards. A few strokes of it in a warm-up, once a week, is a reasonable dose for anybody.

If you cannot yet swim a comfortable freestyle length, learn that first — see freestyle for beginners. Adults working on any new stroke progress far faster with somebody watching from the deck, through private swimming lessons or structured swimming classes. Coached adult training in a masters squad is where most people first attempt butterfly seriously, and where somebody will stop you doing it badly.

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Frequently Asked Questions

Do I need to be strong to swim butterfly?

Less than you think. Timing and body undulation carry the stroke. Strong swimmers with bad timing exhaust themselves in ten metres.

How many kicks per arm cycle?

Two. One as the hands enter, one as they exit. The entry kick is the one beginners omit.

Should I breathe every stroke?

While learning, every second stroke. Every stroke is perfectly acceptable and common among adults. Keep the chin low either way.

Why does my lower back hurt?

Your hips are dropping, usually because you are lifting your head. It is a technique problem. If it persists, see a physiotherapist.

How long before I can swim a length of butterfly?

Months, and that is normal. Practise three to six strokes at a time. Length-swimming with poor technique builds nothing but injury.

Is butterfly worth learning?

For most fitness swimmers, as a drill rather than a distance stroke. It improves everything else. It is also the fastest way to hurt a shoulder if rushed.