Exercise movement reviewed by:Marie Braga, PT, DPT, CSCS

How Iridium Programs This

Iridium uses this variation to isolate the lateral deltoid when sub-muscle fatigue tracking indicates your anterior delts are still recovering from recent heavy pressing. Since performing sets on each side increases workout duration, the algorithm validates your time constraints before swapping this in for faster bilateral raises. Progression is monitored through RPE trends and cumulative volume targets rather than estimated 1RM strength due to the strict isolation mechanics.

Form Cues

Lie completely on your side with your legs stacked or staggered for stability
Lead the movement with your elbow rather than your hand
Raise the dumbbell until your arm is parallel to the floor
Lower the weight slowly for a count of 2-3 seconds
Keep a slight, fixed bend in your elbow throughout the set

Don't

Don't jerk the weight up using hip momentum
Don't raise the dumbbell past shoulder height into a vertical position
Don't allow your wrist to curl or rotate excessively
Don't let your torso rock back and forth during the lift
Don't drop the weight quickly during the lowering phase

Common Mistakes

Using excessive weight
Engaging the upper traps
Leading with the thumb up
Rushing the lowering phase
Rotating the torso for momentum

Muscles Worked

This exercise primarily isolates the lateral head of the deltoid, which is responsible for giving the shoulders their width and 'capped' appearance. By performing this movement lying down, you minimize the involvement of the upper traps and supraspinatus, focusing the load almost entirely on the side delt while the forearms work statically to grip the weight.