How old are you? What’s you’re swimming experience.
While the butterfly is incredibly difficult it doesn’t require much strength. If you can’t complete 50 meters then your stroke is inefficient, you have poor conditioning, you’re unbelievably weak, or a combination of all 3.
Strength training for swimming is pretty puzzling. I personally know a lot of fast swimmers who, despite having very close times in relation to eachother, are vastly different in terms of strength. I know 2 kids who bench 315 and did pretty well at a D3 invite. Of course, I also know that neither of these guys can squat 315 and I doubt any swimmer seriously lifts for their legs.
I also know just by looking at Michael Phelps that he probably has trouble picking up the morning paper and I know for a fact that the only weight training he did before he started squatting last year to train for worlds (He claims in Sports Illustrated he went through brutal squat workouts but I doubt he used more than 135) to improve his leg endurance at the tail end of the 200m butterfly was some light lat-pulldown work because one of he lats was bigger than the other.
Lifting weights will not help improve your butterfly. The only thing that will help improve your butterfly is swimming more butterfly, learning how to look down while you breathe, learning proper hip-motion, bringing your arms straight over the water while keeping them low, and swimming more butterfly.
Think about all the girls who can swim butterfly. All those 9-15 year old girls. I’ve got news for you. They’re weak as kittens.
If you think you basically have your stroke right and you’re training without any coaching, then you need coaching.
That said, your weight program should focus heavily on developing your front delts, your lats, and your triceps. People will tell you that you should do lots of core work in order to learn how to rotate in the freestyle or stay stable in the butterfly. It’s not your core muscles that are moving you. It’s your arms, shoulders, chest, back, and hips. People will also tell you to do movements in the weight room that will mimic swimming motions. I’ve been doing Dumbbell Pullovers for a long time and while the weight I can use has doubled, I can confidently say it has not caused me any major time drops.
Pull-ups
Fat-man Pull-ups
Push-ups
Barbell-Pushups
Dumbbell Lateral Raises
Tricep Extensions
Curls
Front Squats
Dumbbell Power Cleans
If I had to design a weight program for a swimmer I’d have them perform these exercise for 15-50 reps depending on the exercise. The exception would be front squats where I’d have them do a max set of 3-5 only once a week.
I wouldn’t have a swimmer do any overhead pressing. They move their arms overhead more than 1000 times a day. That’s enough of that.
They wouldn’t be doing any heavy lifting with their shoulders. That’s why I’d choose light isolation exercises. I probably wouldn’t emphasize the need for big strength gains and would prefer rep records. My biggest concern would be building up their rear delts and the muscles in their rotator cuffs in order to compensate for all the internal rotation they’re doing.
The best way to train swimming muscles is to use a swim-power-rack (nothing like a squat rack), rubber bands, tiny parachutes or buckets for dragging, paddles, flippers, and a Vasa Swim Bench (Basically a $2,000 Total Gym with Bungie Cords)
If you are a total beginner at swimming and you’ve never been on a team or coached and you’re just hopping in the pool at the YMCA and trying to do fly, then the next best thing you can do besides getting your form looked at is to swim fly with some flippers on. This will allow you to go fast easily so you can get a feel for what good, fast, efficient fly feels like when you swim it.