Reverse Fly With Resistance Bands
Build rear-deltoid strength and correct rounded-shoulder posture with a single resistance band.
Primarily trains: Primarily develops the posterior deltoid through transverse shoulder extension, with secondary activation of the middle trapezius and rhomboids.
Step-by-step demonstration
3 sets × 12–15 reps, 45–60 s rest; the posterior deltoid is a postural endurance muscle — moderate rep ranges with controlled tempo drive hypertrophy better than heavy, low-rep loading.
2-1-2 — a 2-second pull, 1-second squeeze at peak contraction, and a 2-second controlled return to maximise time under tension in a small isolation muscle.
Exhale as you pull your arms out to the sides (concentric); inhale as you slowly return to the start (eccentric).
Step 1 of 2
Setup
Get into position before the first rep.
- 1Anchor the resistance band at chest height — a door anchor, squat rack upright, or sturdy post works well.
- 2Attach a handle to each end of the band, or grip each end directly with an overhand hold.
- 3Stand facing the anchor, roughly 1–1.2 metres away; adjust distance to set your desired starting tension.
- 4Hold one handle in each hand with arms extended straight toward the anchor, palms facing each other, wrists neutral.
- 5Hinge slightly at the hips (10–15°), brace your core, and set your shoulder blades — neither shrugged nor collapsed.
Step 2 of 2
Execution
The actual movement, one rep.
- 1Begin with both arms extended at shoulder height, pointing toward the anchor, elbows soft (5–10° bend — not locked).
- 2Exhale and drive both arms out to the sides in a wide arc, leading with the elbows, keeping them at shoulder height throughout.
- 3Stop when your arms are in line with your torso — roughly a 'T' position — and squeeze the posterior deltoids and mid-traps at peak contraction.
- 4Pause for one count at the end range; do not let the shoulder blades wing forward.
- 5Inhale and slowly return your arms back to the starting position along the same arc, resisting the pull of the band — this eccentric phase builds the most tissue stress.
- 6Reset your shoulder position before initiating the next rep.
Form cues
What a good coach would say in your ear.
- Lead with the elbows, not the hands — imagine pushing the walls apart.
- Keep elbows at ear-to-ear height; if they drop, the load shifts off the posterior delt.
- Pinch shoulder blades together at the top — you should feel the squeeze between them.
- Chin stays neutral; do not jut the head forward as the band pulls back.
- Control the return — a slow negative is where the real work happens.
Avoid these
Common mistakes.
The technique errors that quietly undo your training.
- Shrugging the shoulders upward: recruits the upper trapezius instead of the posterior delt, reducing effectiveness and stressing the neck.
- Bending the elbows too deeply (past 30°): converts the movement into a row, shifting load to the lats and biceps rather than isolating the rear shoulder.
- Allowing the torso to rotate or lean back: introduces momentum and reduces the isolated stimulus on the posterior delt.
- Dropping the arms below shoulder height mid-rep: changes the line of pull and reduces posterior delt activation.
- Rushing the eccentric (return) phase: wastes the most mechanically advantageous part of the rep for muscle development.
Variations & progressions
Make it harder. Make it easier. Make it fit.
- Seated reverse fly with band (anchored low): reduces lower-body compensation and is useful for those with lower-back sensitivity.
- Single-arm reverse fly: increases unilateral demand and exposes side-to-side strength imbalances.
- Dumbbell reverse fly on incline bench: removes band variable; useful progression when consistent loading is preferred.
- Cable reverse fly (cable machine): provides constant tension through the full arc — a natural step up from bands.
Safety
Avoid this exercise if you have an acute rotator cuff tear or active shoulder impingement — the transverse abduction pattern can aggravate both. If you have a history of shoulder instability, begin with very light band tension and keep the range of motion within pain-free limits. Do not anchor the band above head height, as this changes the line of pull and increases impingement risk. Stop immediately if you feel sharp or pinching pain inside the shoulder joint rather than muscular fatigue.
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