The dumbbell rear delt fly, otherwise known as the rear delt raise, is an isolation type weighted resistance exercise primarily used to train certain muscles located on the upper body. Oftentimes performed with low weight dumbbells and a high number of repetitions, the dumbbell rear delt fly is prescribed by physical therapists and coaches for a variety of purposes related to muscular function.
Because of its muscle isolating nature, the dumbbell rear delt fly is usually added to rehabilitation regimens or workout programs as an accessory exercise meant to facilitate strength and muscular hypertrophy gains in the shoulder muscles.
The dumbbell rear delt fly is a bilateral dumbbell exercise with a closed kinetic chain, making it excellent as an isolation exercise for the deltoid muscle group located on the shoulders, with a particular focus on the rear and lateral deltoid heads. This roughly translates to an excellent supplementary exercise, not only for the function of the rotator cuff but also acromioclavicular joint and the shoulder muscles themselves.
The dumbbell rear delt fly is a closed kinetic chain isolation exercise fittingly performed with the use of a pair or a single dumbbell weight, primarily added to physical rehabilitation programs and workout regimens in order to aid in the development of the shoulders, its various connective tissue bodies and the trapezius muscles located behind the neck.
As is clear in its name, the only requirement to perform the dumbbell rear delt fly is a pair of evenly weighted dumbbells and an open space large enough to spread the exerciser’s arms outwards to their full extension.
The dumbbell rear delt fly primarily utilizes transverse abduction wherein the hands are kept in a neutral or near neutral grip position as the arms are drawn upwards with the elbows slightly bent, making the lateral deltoid head a synergist or assistive muscle instead of the primary activated muscle, of which is clearly the rear deltoid head.
The dumbbell rear delt fly is relatively easy to perform so long as the exerciser retains the function of their shoulders and has no history of injury in the rotator cuff or acromioclavicular joint.
To begin, the exerciser will stand with their core somewhat relaxed and their feet placed at a comfortable distance apart. In their hands, a pair of evenly weighted dumbbells must be gripped in a neutral position with the palm facing inward so as to allow the full range of motion of the shoulders to be realized.
Maintaining a straight back and relaxing the scapula without winging it, the exerciser will then bend at the waist at a comfortable angle. If needed, the exerciser may rest their head against an incline bench or similar surface.
Elbows slightly bent, the exerciser must subsequently raise both arms simultaneously upwards, raising the dumbbells approximately 90 degrees away from the torso or until the wrists are somewhat parallel with the shoulders vertically.
Concentric portion of the exercise completed, all that is required of the exerciser after this point is to allow the dumbbells to fall back into their original position in a controlled manner, ensuring that the deltoid muscle groups are evenly flexed so as to reduce the chance of injury.
It is advisable to perform this exercise with a relatively low amount of weight and many repetitions owing to its isolation nature and the fragility of an untrained rotator cuff joint.
The dumbbell rear delt fly is a particular favorite among certain groups of physical therapists and athletic coaches owing to its relatively simplistic nature and the ease at which it may be performed without sacrificing any recovery or training benefits provided by the exercise.
The rear deltoid is, among other things, one of the primary muscles responsible for the retraction of the scapula and subsequently affects proper posture of the upper torso, of which may result in injury if left untrained.
Additionally, the use of the trapezius muscle as a secondary activated muscle group will aid both in neck posture and in the general health of the cervical section of the spine, reducing neck pain and minimizing the risk of injuries to said area, such as whiplash from car accidents or similar injuries.
Much like the majority of weighted resistance exercises, the dumbbell rear delt fly provides a myriad of health benefits as well as a few specific ones that are unique to the rear delt fly.
Primarily, the dumbbell rear delt fly will cause a noticeable increase in bone mass, reinforcing the muscular skeletal system throughout the exerciser’s body. This is bolstered by the reinforcement of connective tissue located in the rotator cuff, elbow, wrists, and AC joint, all of which directly undergo mechanical tension as the exercise is performed.
At a chemical level, any sort of weighted resistance exercise triggers a measurable increase in various anabolic hormones, improves insulin sensitivity of the body’s cellular machinery as well as improves cognitive function through the enhancement of cardiovascular health.
In fact, the dumbbell rear delt fly is capable of producing angiogenesis, or the creation of new blood vessels, through its increase of the HGH and IGF-1 anabolic hormones. In turn, this improves general circulatory health as the heart is also exercised to some extent, depending on the speed and volume of repetitions involved in the exercise.
The athletic training benefits to the dumbbell rear delt fly is primarily through its use as a facilitatory exercise in terms of muscular hypertrophic growth as well as neuromuscular recruitment training.
Considering the fact that the dumbbell rear delt fly is generally used as a low weight and high volume isolation exercise, it is best performed after heavier and more intense compound exercises have already been completed, with the dumbbell rear delt fly acting as a “finisher” for the deltoid muscle group so as to maximize strength and hypertrophy gains.
Additionally, the dumbbell rear delt fly aids in static flexion strength as the top or peak of the repetition, if performed properly, utilizes this very same kind of strength, of which is vitally important for a muscle group such as the deltoids owing to the fact that they are used in nearly every upper body exercise.
While the dumbbell rear delt fly is generally considered to be a safe exercise when used with proper form and a reasonable amount of weight, there are a few drawbacks to performing this exercise, some of which only pertain to a certain subset of exercisers.
The first of these drawbacks is the fact that the dumbbell rear delt fly utilizes less of the lateral and anterior head of the deltoid muscle trio, of which may cause muscular imbalances and an uneven appearance in individuals that do not balance this out with subsequent anterior deltoid isolation exercises or compound movements.
Additionally, individuals with a history of rotator cuff injuries, pectoralis minor tears, trapezius tears or similar upper body soft tissue injuries may find that the dumbbell rear delt fly could aggravate these previous injuries or even cause new ones, owing to the angle at which the weight is raised during the exercise.
Another drawback to performing the dumbbell rear delt fly is the relatively low amount of weight that may be reasonably used, as certain individuals may find that other muscle groups in their upper body are too strong and can subsequently direct more force than is needed, taking away the intended training stimuli from the deltoid muscles.
The dumbbell rear delt fly primarily activates the rear deltoid head, with the lateral and anterior head acting as stabilizers and contributing somewhat to the force output of the deltoid muscle group as a whole.
Apart from the deltoids, the dumbbell rear delt fly also activates the trapezius somewhat, especially in instances wherein the dumbbells are raised parallel or higher than the shoulders themselves.
As the dumbbell rear delt fly is an isolation exercise, it is intended to only train a single muscle group, and as such does not provide the wide reaching muscle activation of compound exercises. This, of course, is only true if the dumbbell rear delt fly is being performed with the proper form.
The dumbbell rear delt fly, like most isolation exercises, is generally used as a supplemental exercise in order to work on muscular imbalances or areas of particular weakness in the athlete.
It is most often added to the end of exercise routines so as to leave sufficient enough energy and muscular glycogen for the more intense compound exercises, of which are usually performed first, while the exerciser’s body is still fresh.
In certain programs such as the “bro split” or similar routines, the dumbbell rear delt fly is likely part of an entire workout session dedicated solely to the deltoid muscle group or other muscle groups related anatomically or functionally to the deltoid muscles.
As the rear head of the deltoid muscle group is generally a neglected muscle owing to the fact that it is difficult to directly activate during non-specific compound exercises, the dumbbell rear delt fly is an advisable addition to nearly every exercise or physical rehabilitation routine, so long as it is performed with a reasonable amount of weight and at the proper time.
Before doing so, of course, it is best to consult an athletic coach or physical therapist, so as to understand how to best incorporate the dumbbell rear delt fly into your exercise routine.
1. Campos YAC, Vianna JM, Guimarães MP, et al. Different Shoulder Exercises Affect the Activation of Deltoid Portions in Resistance-Trained Individuals. J Hum Kinet. 2020;75:5-14. Published 2020 Oct 31. doi:10.2478/hukin-2020-0033
2. Lars L Andersen, Michael Kjær, Christoffer H Andersen, Peter B Hansen, Mette K Zebis, Klaus Hansen, Gisela Sjøgaard, Muscle Activation During Selected Strength Exercises, Physical Therapy, Volume 88, Issue 6, 1 June 2008
3. Westcott WL. Resistance training is medicine: effects of strength training on health. Curr Sports Med Rep. 2012 Jul-Aug;11(4):209-16. doi: 10.1249/JSR.0b013e31825dabb8. PMID: 22777332.