A fly or flye is a

strength training Strength training or resistance training involves the performance of physical exercises that are designed to improve strength and endurance. It is often associated with the lifting of weights. It can also incorporate a variety of training te ...

exercise in which the hand and

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

move through an arc while the

elbow The elbow is the region between the arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and the me ...

is kept at a constant angle. Flies are used to work the muscles of the upper body. Because these exercises use the arms as

lever A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is d ...

s at their longest possible length, the amount of weight that can be moved is significantly less than equivalent press exercises for the same muscles (the

military press The overhead press is an upper-body weight training exercise in which the trainee presses a weight overhead while seated or standing. It is mainly used to develop the anterior deltoid muscles of the shoulder. The standing version was once a compon ...

and bench press for the shoulder and chest respectively). Due to this leverage, fly exercises of all types have a large potential to damage the shoulder joint and its associated ligaments and the tendons of the muscles connecting to it. They should be done with caution and their effects first tested while using very light weights; which are gradually incremented after more strength is gained.

Equipment

Flies can be performed using any weight that can be held in the hand. The simplest equipment to use is a

dumbbell The dumbbell, a type of free weight, is a piece of equipment used in weight training. It can be used individually or in pairs, with one in each hand. History The forerunner of the dumbbell, halteres, were used in ancient Greece as lifting ...

, though the exercise can also be performed using a cable machine. Flies can be performed supine, sitting or standing upright. When using a cable machine, the hands and arms move through the same

anatomical plane An anatomical plane is a hypothetical plane used to transect the body, in order to describe the location of structures or the direction of movements. In human and animal anatomy, three principal planes are used: * The sagittal plane or latera ...

as the dumbbell version. Using dumbbells for pectoral flies requires the use of stabilizer muscles associated with performing flies, when compared to performing flies with a cable machine. Flies can also be performed with body weight by doing gymnastic ring chest flies.

Chest fly

The chest fly or pectoral fly (abbreviated to pec fly) primarily works the

pectoralis major muscle The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, ...

s to move the arms horizontally forward. If medially (internally) rotated, it is assisted in this by the anterior (front) head of the

deltoideus The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up o ...

in transverse flexion. If laterally (externally) rotated, the contribution of the deltoid is lessened and the pec major is strongly emphasized as the transverse adductor. The hands are usually brought out further than the elbows, in which case the flexors contract isometrically to inhibit undesired excess extension of the elbow. Muscles which do this are the biceps brachii, the brachialis and the

brachioradialis The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by ...

. The biceps may also play a limited role in shoulder flexion. The straighter the elbow is, the more stretch in these muscles. For safety, many avoid locking out the joint. The movement is performed lying on the back on a bench, starting weights extended above the chest, meeting at the midsagittal plane. The arms are lowered through an arc passing through the

transverse plane The transverse plane (also known as the horizontal plane, axial plane and transaxial plane) is an anatomical plane that divides the body into superior and inferior sections. It is perpendicular to the coronal and sagittal planes. List of c ...

, terminating when the arm is roughly

parallel Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster of ...

to the floor, then returning to the starting position and repeating. This exercise can be done using other implements than

s, such as

kettlebell In weight training, a kettlebell is a cast-iron or Steel casting, cast-steel ball with a handle attached to the top (resembling a cannonball with a handle). It is used to perform many types of exercises, including Ballistic Training, ballist ...

s or weight plates. There are also machines such as the pec deck which perform a stabilized version of the movement while allowing people to sit upright. Butterfly-machine-2.png, Butterfly machine fly (pec deck) start Butterfly-machine-1.png, Butterfly machine fly (pec deck) end Dumbbell-flys-2.png, Dumbbell fly start Dumbbell-flys-1.png, Dumbbell fly end If using a cable machine, the body leans forward to counterbalance the weight moved, with the feet braced and the elbows are positioned slightly below shoulder height. The arms move the same arc as a bench fly, relative to the

torso The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a huma ...

. Cable-crossover-2.png, Cable crossover fly start Cable-crossover-1.png, Cable crossover fly end Crossover-with-bands-2.png, Crossover w/bands start Crossover-with-bands-1.png, Crossover w/bands end Flat-bench-cable-flys-2.png, Lying cable fly start Flat-bench-cable-flys-1.png, Lying cable fly end

Incline

The clavicular portion of the pectoralis major is targeted through incline flies, when the arms rise upward as they adduct. Incline-cable-flyes-2.png, Incline cable fly start Incline-cable-flyes-1.png, Incline cable fly end Incline-flys-2.png, Incline dumbbell fly start Incline-flys-1.png, Incline dumbbell fly end Incline-flys-with-a-twist-2.png, Twisting fly start Incline-flys-with-a-twist-1.png, Twisting fly end In flies the shoulders are sometimes externally (laterally) rotated to point the elbows down to shift emphasis away from use of the

anterior deltoid The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up ...

as a transverse adductor. Recordsetter World Record holder Jason Faulkner (Incredible Faulk) is featured in a video Completing 47 lifts with 65 Lb. Dumbbells in 1 minute. This surpasses Eamonn Keane's Guinness Record by 1,200 Pounds for Most weight Incline fly lifted in 1 minute.

Inverted fly

The inverted fly (also known as a bent-over lateral raise, reverse fly, or rear delt fly) works the posterior deltoid. This movement is the opposite of a chest fly. The exercise is performed with the torso parallel to the ground, facing down, with the hands in front of the face. Arms are moved through the

in an arc until parallel to the ground (or the limit of the range of motion of the

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder mak ...

is reached), then returned to the starting position and repeated. In terms of glenohumeral movement, the posterior deltoid does not work alone, and is assisted by other muscles. If the shoulder is neutrally rotated (elbows pointing outward then towards the scapulae as they lift) the posterior deltoid will be assisted in this transverse extension by the lateral rotators of the

rotator cuff The rotator cuff is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspi ...

: the

infraspinatus In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.''Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspin ...

and

teres minor The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...

. If the shoulder is externally rotated (elbows pointing towards the hips) then it will be assisted in this transverse abduction by the middle deltoid head. This fly, while it seems like an isolation movement, is actually a compound movement because it involves movement in a second joint: the scapulothoracic. The scapulae will retract (adduct) during this type of fly. The muscles that perform this function are the rhomboids and the

trapezius The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports th ...

. If the lifter drops their elbows closer to their hips (rather than bringing them outward) the latissimus dorsi will come into play and deemphasize the use of the aforementioned muscles that cross both joints, as the lats bypass the scapulae and attach directly to the lumbar fascia. A variation involves sitting upright and using a cable machine; the machine is next to the shoulder opposite the muscle being worked (in line with the

coronal plane The coronal plane (also known as the frontal plane) is an anatomical plane that divides the body into dorsal and ventral sections. It is perpendicular to the sagittal and transverse planes. Details The coronal plane is an example of a longit ...

), and the hand moves through the transverse plane across the front of the body at approximately eye level.

Shoulder fly

The shoulder fly (also known as a lateral raise) works the

deltoid muscle The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up o ...

of the shoulder. The movement starts with the arms straight, and the hands holding weights at the sides or in front of the body. Body is in a slight forward-leaning position with hips and knees bent a little. Arms are kept straight or slightly bent, and raised through an arc of movement in the

that terminates when the hands are at approximately shoulder height. Weights are lowered to the starting position, completing one "rep". When using a cable machine the individual stands with the coronal plane in line with the pulley, which is at or near the ground. The exercise can be completed one shoulder at a time (with the other hand used to stabilize the body against the weight moved), or with both hands simultaneously if two parallel pulleys are available. This movement, when the shoulder is kept in neutral rotation, primarily targets the middle head of the deltoid. The anterior (front) and posterior (back) heads of the deltoid will also co-contract to aid in the abduction function. If the shoulder is laterally (externally, outwardly) rotated, the anterior deltoid becomes the prime mover of the glenohumeral joint, the posterior deltoid de-activates, and the middle head assists. By bending at the waist or leaning against a bench, the line of pull created allows the lateral deltoid to be isolated to a higher degree. The Complete Guide to Side Lateral Raises
/ref> If repetitions are done explosively, it is possible for form to deteriorate and other muscles may come into play to do work instead of the deltoid, by generating upward and rotation momentum. The muscles which can be used to "cheat" in this movement are primarily the

serratus anterior The serratus anterior is a muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. The serratus anterior acts to pull the scapula fo ...

and the upper fibers of the

, both of which elevate and upwardly rotate the scapulae. Dumbbell-lateral-raises-2.png Dumbbell-lateral-raises-1.png

Common errors

* External rotation of shoulder - If external rotation occurs during the lift, the rotatory cuff muscles are activated. If the weight is lifted while the shoulder is in the externally rotated position, the anterior deltoid does all the work. In both cases, utilisation of the lateral deltoid is decreased to a great extent thereby defeating the purpose of the exercise. * Shoulder extension - Shoulder extension occurs when the elbows travel behind the shoulders during the lift. This movement, too, decreases the utilisation of the lateral deltoids. * Throwing the weight up - Using the hips or spine to generate momentum also lessens the emphasis on the lateral deltoids. * Complete upright position - Keeping the body totally straight increases the chances of the anterior deltoid being used.