is rear delt shoulder or back

Many gymgoers wonder whether the rear delts are shoulder or back muscles.

It’s easy to see why there’s confusion. 

Anatomically, they’re part of the deltoids (shoulder muscles). But because they sit on the back of your shoulder joint and are only visible from behind, they look more like a back muscle.

Moreover, one of their main functions is horizontal shoulder abduction—moving your arms away from your body’s midline while keeping your upper arms parallel to the floor. Therefore, they play a much greater role in “pulling” exercises like pull-ups and rows than in traditional shoulder exercises where you press overhead. 

In other words, while the rear delts are technically part of your shoulders, they often work hardest when you’re training your back.

Which raises the question: Should you train your rear delts on shoulder or back day?

For most, the best approach is both.

Here’s an effective plan:

  • Focus on pulling exercises that emphasize the rear delts on back or pull day.
  • Add 3-to-6 sets of rear delt isolation exercises to a shoulder workout later in the week.

For example:

Workout #1: Back Day

  • Barbell Row: 3 sets | 4-to-6 reps | 3-to-5 min rest
  • Pull-up: 3 sets | 4-to-6 reps | 3-to-5 min rest
  • Seated Cable Row: 3 sets | 6-to-8 reps | 2-to-3 min rest
  • Dumbbell Rear Lateral Raise: 3 sets | 6-to-8 reps | 2-to-3 min rest

Workout #2: Shoulder Day

  • Overhead Press: 3 sets | 4-to-6 reps | 3-to-5 min rest
  • Dumbbell Side Lateral Raise: 3 sets | 6-to-8 reps | 2-to-3 min rest
  • Barbell Rear Delt Row: 3 sets | 6-to-8 reps | 2-to-3 min rest
  • Machine Reverse Fly: 3 sets | 6-to-8 reps | 2-to-3 min rest

And if you’d like to optimize your rear delt training even further, check out this article:

The 10 Best Rear Delt Exercises for Shoulder Mass and Strength