Butterfly to improve freestyle?

What aspect can improve in your freestyle by learning butterfly?

The key elements of butterfly swimming that contribute to freestyle swimming:

During the recovery you are also doing reverse fly exercise. This resistance exercise is also a part of a whole body anaerobic fitness program according to many personal trainers in the fitness centers. Reverse dumbbell flyes strengthen the posterior shoulder and upper back. Strength and development in the rear shoulders and thoracic spinal muscles, improves upper body posture, function and movement. The correct balance of strength between the muscles that pull the shoulder backward and the muscles that pull the shoulder forward are necessary for proper posture and correct functional movement. Proper posture and function is essential to a pain-free performance of swimming of activities of daily living and increased athletic performance.

The butterfly stroke relies heavily on the arm and shoulder muscles to propel the body forward in the water. When the arms make a rotating motion through the water, this builds the deltoid muscles, which are on the front and back of the shoulders. This action also builds the trapezius muscles, which are situated beside the shoulders on either side of and behind the neck. The biceps and triceps muscles play a smaller role in the butterfly stroke. In butterfly both arms should be kept straight because these muscles are used to slice through the water, if you gain this as a habit, this will provide you robust stability for freestyle swimming.

In the forums as you always discuss core body exercises and strengthening the core muscles, tend to do but have never done yet  , "the core muscles", those muscles that make up the abdomen and the back, are of vital importance to swimmer's power. The abdominal muscles provide the strength to lift out of the water, then curve in to return. The latissimus dorsi muscles of the back, which give swimmers their V-shape torso appearance, are also relied upon to provide stability to the motion and to push against the water when the arms are below the surface. Swimmers with well-developed core muscles are better protected against injury because the core muscles protect the back from injury.

As for the legs; other swimming strokes require the legs to kick individually to move the body forward. Instead, the butterfly stroke requires the legs to move as one unit. This requires special strength in the gluteus muscles and iliopsoas. The hamstring muscles, situated on the backs of the legs, also are extremely important because the legs must kick in a backward motion instead of the scissoring motion used in most other swimming strokes. As might be understood the iliopsoas muscle is major in butterfly.

The Iliopsoas(known as the "Muscle of The Soul" - oftenly called Psoas) is the deepest muscle of the human body affecting our structural balance, muscular integrity, flexibility, strength, range of motion, joint mobility, and organ functioning. Growing out of both sides of the spine, the psoas spans laterally from the 12th thoracic vertebrae (T12) to each of the 5 lumbar vertebrae. From there it flows down through the abdominal core, the pelvis, to attach to the top of the femur (thigh) bone. The Psoas is the only ‘muscle’ to connect the spine to the legs.  It is responsible for holding us upright, and allows us to lift our legs in order to walk and for freestyle swimming to flutter kick. A healthily functioning psoas stabilizes the spine and provides support through the trunk, forming a shelf for the vital organs of the abdominal core.

A tight psoas not only creates structural problems, it constricts the organs, puts pressure on nerves, interferes with the movement of fluids, and impairs diaphragmatic breathing.

In fact, “The psoas is so intimately involved in such basic physical and emotional reactions, that a chronically tightened psoas continually signals your body that you’re in danger, eventually exhausting the adrenal glands and depleting the immune system.” Some visual info about iliopsoas:
https://www.youtube.com/watch?v=PweqtbDr4wI
https://www.youtube.com/watch?v=8tdhp504y34&t=15s
https://www.youtube.com/watch?v=VcrzfTSCZEs

"The Catch" Phase:
Catch phase of butterfly is very similar to freestyle, stroke includes the hands entry into the water. The body begins from the initial position in the water: prone position, head flexed downward and facing down, hands extended above head at shoulder length, legs extended, feet planterflexed, trunk extended. The hands penetrate the water pronated with thumbs first. The arms the depress simultaneously into the water. The arms then horizontally abduct, forming a "Y" shape. The hips flex while the legs remain extended, projecting the gluteal region out of the water. Hands should enter soft and the trunk should undergo natural flexion. Muscles:
erector spinae
rectes abdominis
iliacus, psoas major and psoas minor
semitendinosus, semimembranosus, and biceps femoris muscles
sternocleidomastoid
gastrocnemius and soleus
deltoid and trapezius
pronator teres and pronator quadratus
adductor magnus, adductor brevis and adductor longus
gracilis and pectineus
extensor digitorum
vastus intermedius, medialis, and lateralis, and rectus femoris muscles

"The Frontsweep" Phase:
This phase begins propulsion through water. To start this phase, the arms circumduct symmetrically outward. The right arm moves clockwise and the left counterclockwise. The arms protract down into the water as the body is submerged naturally. The arms continue to abduct horizontally until they are at a 90 degree angle with the body. As they are abducting, the forearm flexes at the elbow to create a 120 degree angle. This keeps the elbow superior to the forearm. The trunk goes from a flexed position to an extended position, straightening the body out. Also the knees now begin to flex, and the hips remain flexed as well. Muscles:
trapezius, rhomboid major and rhomboid minor muscles
biceps brachii, brachialis, and brachioradialis
serratus anterior and pectoralis minor
pectoralis major
gluteus maximus,minimus, and medius
rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius
iliacus, psoas major/minor, biceps brachii, semitendinosus, and semimembranosus
gastrocnemius and soleus

"The Backsweep" Phase:
This phase generates the most drive through water. It is essentially when the athlete pushes back and propels forward swiftly. From the angle created in phase 2, the arms begin to extend at the shoulder and horizontally adduct. The forearms flexes at the same time even more until the hand are almost touching and under the abdomen. This makes the arms circumduct backwards. Once the arms and hands pass under the body the forearms quickly extend and the arms abduct and hyperextend at the shoulder. This movement is synchronized with a second leg kick, in which the hips and knees go from being flexed, to extending rapidly. The second kick should ALWAYS be stronger than the first. This propels the body forward as the body undulates. The hips sink into the water and the head naturally pops out. This is the small window in which a breath should be taken. Muscles:
erector spinae
trapezius
vastus intermedius, vastus lateralis, vastus medialis, and rectus femoris
iliopsoasic muscles.
trapezoid, rhomboid major, rhomboid minor
supraspinatis muscle
triceps brachii
biceps brachii, brachialis, and brachioradialis
pectoralis major, latissimus dorsi, and coracobrachialis
Deltoid, upper fibers of trapezius

"The Recovery" Phase:
The recovery phase is basically a quick transition back to the initial potition and first phase. The arms should be hyperextended behind the body from the last phase. The arms now circumduct symmetrically forward.The right arm is now moving counter-clockwise and the left is moving clockwise. The arms are abducting with thumbs facing forward unti the arms are perpendicular to the body. Then they continue to the fron of the body with lateral flexion of the shoulder. The forearms should be slightly flexed in order to keep the elbow above the arm and water. As the arms move forward they pronate again, facing the thumbs downward towards the water. When the arms circumduct forward, the head and trunk flex downward, making them parallel with the water. The hip follows as it slightly flexes. The knees flex as well, getting ready for the first kick. Muscles:
supraspinatis
posterior deltoid, trapezius, rhomboid major, and rhomboid minor
pectoralis minor
biceps brachii, brachialis, brachioradialis
sternocleidomastoid
iliacus
psoas major and psoas minor
biceps femoris, semitendinosus, semimembranosus
gastrocnemeus, soles
gracilis
pectineus

Butterfly is also the most calorie burning stroke:
For the king of calorie-burning swimming workouts, though, swim an hour doing butterfly (if you dare). The calorie torching ranges from 649 calories for a 130-pounder to 1,024 calories for a 205-pounder. Where as in freestyle:
- A 130-pound person swimming freestyle for one hour will burn 590 calories swimming fast, and 413 calories swimming slower.
- A 155-pound person swimming freestyle for one hour will burn 704 calories swimming fast, and 493 calories swimming slower.
- A 180-pound person swimming freestyle for one hour will burn 817 calories swimming fast, and 572 calories swimming slower.
- A 205-pound person swimming freestyle for one hour will burn 931 calories swimming fast, and 651 calories swimming slower.

All in all, butterfly swimming is a perfect rehabilitation and fitness exercise for not only freestylers but also for everyone who wants to be more fit in the water.

Additional Information(again):
Manmaker exercises are also great for core(abs, erector spinae, glutues, iliopsoas), shoulder, latisus dorsi, scapula, trapezius, pectoral muscles' strengthening, flexibility and stability. Manmaker exercise allows you to feel more stronger, thus comfortable and stable in the water and swim faster.

Very recently I discovered breastroke lifting the upperbody out of the water is easier when bending the lower back to ribcage more. This keeps the hips and legs traveling more horisziontally forward, not disturbed so muxh  by the upperbody action.
This combined with diving in after that felt a bit like a butterfly type movement.
Funny how focus on a more loose and independant upperbody relative to hips in freestyle can influence other strokes.

Woow, have you recorded any videos swimming butterfly? lets see, maybe we can learn new things.

SA wrote:What aspect can improve in your freestyle by learning butterfly?

Shoulder articulation/flexibility, recovering both arms at the same time is a bitch.

I cant swim butterfly , so I wondered what can be gained by learning it.

i used to swim 30secs for 50m when i was 17 years, now i can swim 32 secs, with an intensive 1 month preparation including kicking and drills and also underwater actions i can again pull it to 30, maybe 29 secs. butterfly is a stroke of rhythm, i love it, try to understand the rhythm and never swim more than 15m at the outset while setting up the technique.