Dumbbell Flys (How To, Muscles Worked, Benefits)

The Dumbbell Fly is an isolation exercise that targets the chest by stretching and contracting the pecs through a wide arc of motion. It’s a great move for building muscle definition and improving mind-muscle connection in the chest. Unlike pressing exercises, flys minimize triceps involvement and put more direct tension on the chest.

Primary Muscles Worked: Pectoralis Major
Secondary Muscles Worked: Anterior Deltoids, Biceps (Stabilizers)
Equipment Needed: Dumbbells, Flat Bench

How To Do Dumbbell Flys

Step-by-Step Instructions

Set-Up:
- Lie flat on a bench holding a dumbbell in each hand.
- Start with your arms extended above your chest, palms facing each other, and a slight bend in your elbows.
- Engage your core and keep your shoulder blades pulled back into the bench.
Execution:
- Slowly lower the dumbbells out to your sides in a wide arc, maintaining the bend in your elbows.
- Lower until your upper arms are roughly parallel with the floor or until you feel a stretch in your chest.
- Reverse the motion by squeezing your chest to bring the dumbbells back together at the top.
Tips for Proper Form:
- Keep the movement slow and controlled—especially during the lowering phase.
- Don’t let the dumbbells drop too low or go behind your shoulders.
- Avoid locking out your elbows or turning the move into a press.

Key Benefits

Isolates the chest for improved muscle definition and shape.
Enhances flexibility and range of motion through the pecs.
Builds control and helps improve activation in chest-focused movements.

Modifications and Variations

Easier Option: Use lighter dumbbells or perform the exercise on the floor to limit the range of motion.
Harder Option: Increase weight, add a pause at the bottom, or perform on an incline bench to target the upper chest.

Common Mistakes

Using Too Much Weight: Go lighter than your pressing weight to avoid straining the shoulders.
Turning It Into a Press: Keep the elbows slightly bent and fixed—don’t bend and straighten them like a press.
Going Too Deep: Only lower until you feel a good stretch in the chest; don’t sacrifice control for range.

Reps and Sets Recommendations

For Beginners: 3 sets of 10–12 reps with light dumbbells.
For Hypertrophy: 3–4 sets of 8–12 reps, focusing on slow and controlled movement.
As a Finisher: 2–3 sets of 12–15 reps with light weight and minimal rest.

Dumbbell Fly Alternatives

Don’t have dumbbells? Want to add some variety to your workout? Whatever the reason, if you need an alternative for Flys, here are a few exercises you may be able to try out.

Incline Dumbbell Flys

If you’re just looking to add a little variety to your workout, try your flys on an incline. Simply adjusting your bench up to about 45 degrees and doing Incline Dumbbell Flys can really change the feel of the exercise.

Med Ball Chest Pass

Stand in an athletic position with a lighter medicine ball (for most, 10-15 pounds will work well here). Extend the hips and aggressively chest pass the ball into the wall or to a partner. This should be fast and explosive.

Medicine Ball Chest Passes are also a great warm-up exercise for athletes getting ready for a bench day.