Butterfly Swim
- Advanced
- Bodyweight
Butterfly moves both arms together: they enter overhead, pull through under the body and recover over the surface while the legs beat as one in a dolphin kick. Electromyographic analysis of twelve shoulder muscles found pectoralis major and latissimus dorsi generating the power through the pull, deltoids and rotator cuff controlling entry and recovery, and serratus anterior and subscapularis staying active throughout, so shoulder load runs continuously through the stroke cycle. The body teeter-totters around the hips, so the trunk works continuously to hold the rhythm.
How to do the Butterfly Swim
- Start prone with your body long and both arms extended in front of you.
- Press both hands out and down together, keeping the elbows high.
- Drive both arms back past your hips to finish the pull.
- Sweep both arms over the water simultaneously into the next entry.
- Beat both legs together in a dolphin kick timed to the entry and the finish.
- Breathe forward once every second or third cycle as the arms clear the water.
Muscles worked
- Primary:
- Back and Chest
- Secondary:
- Shoulders, Core, Triceps, and Traps
Why train it
- Loads back, chest and shoulders through the widest range of the four strokes.
- Demands whole-body timing between the arm pull, kick and body wave.
- Delivers the highest intensity of the competitive strokes for short efforts.
Common mistakes
- Lifting the head high to breathe, which sinks the hips and stalls the recovery.
- Pulling with the arms only, so the body wave and kick stop contributing.
- Mistiming the second kick, which leaves the arms to drag the body through the entry.
- Swimming long sets while fatigued, exactly when shoulder mechanics start to break down.
Frequently asked questions
What muscles does the Butterfly Swim work?
The Butterfly Swim trains the back and chest as the main targets. Expect the shoulders, core, triceps, and traps to take some of the load as well.
What equipment do I need for the Butterfly Swim?
None. The Butterfly Swim is a bodyweight movement, so your own weight is the resistance and floor space is the only requirement.
Is the Butterfly Swim suitable for beginners?
Not as a starting point. The Butterfly Swim is rated advanced: it asks for control under load that only comes from months of easier work, and the cost of a bad rep is higher here than it is anywhere else on this page. Build up to the Butterfly Swim through the alternatives below.
Can I do the Butterfly Swim at home?
Yes, anywhere. There is nothing to buy and nothing to set up, which makes the Butterfly Swim one of the movements worth keeping for days you never reach a gym.
How many sets and reps of the Butterfly Swim should I do?
Work in time, not reps: 10 to 30 minutes steady, or 20 to 40 second efforts with equal rest when you want intervals. Two or three sessions a week sits well alongside lifting.
What are good alternatives to the Butterfly Swim?
Swim Sprint Intervals, Man Maker, and Rowing Intervals train the same primary muscles as the Butterfly Swim. Pick whichever one matches the equipment in front of you.