Side Delts Training for the Slim Woman: 135 to 160 lbs, Recomp Phase

For a woman at 135 to 160 pounds in a recomp, I train side delts with cable, dumbbell and machine lateral raises. Do it on upper body days of a four-day upper/lower split, add weight when every set reaches the top of the rep range, and expect visible change in about 8 to 12 weeks.

Slim is my name for women between 135 and 160 pounds, usually a pear, hourglass or inverted triangle shape, in a recomp phase: losing fat and building muscle at the same time on 1,700 to 2,000 calories and 120 to 145 grams of protein a day.

If you have read the full shoulder protocol and you want to go deeper on the lateral deltoid specifically, the muscle that creates shoulder width and makes your waist look narrower by contrast, this article is that deeper dive.

The lateral deltoid is isolated only by lateral raise movements. No compound exercise, no bench press, no overhead press, no row, no pull-up, trains it significantly. If you are not doing dedicated lateral raises with progressive overload, your lateral deltoids are not being trained. Full stop.

What muscles are you training in your side delts?

The lateral deltoid originates along the acromion, the bony point of your shoulder, and inserts at your upper arm alongside the other deltoid heads. Its function is shoulder abduction: raising your arm out to the side away from your body. This is the only movement that isolates the lateral deltoid. Pressing movements (bench press, overhead press) work the anterior deltoid and the lateral deltoid in the lower portion of the pressing range but do not produce the full abduction movement needed for complete lateral head development. Lateral raises in various forms are the only way to develop shoulder width.

What is the exact side delts workout for Slim?

Exercise 1: Cable Lateral Raise (One Arm)

Set a low cable pulley. Stand beside the machine, holding the cable handle in the far hand, the hand on the opposite side from the machine. Your arm crosses in front of your body at the start position. Raise the handle out to the side and upward until your arm reaches shoulder height. The cable provides resistance throughout the full range of motion, including the bottom position where dumbbells provide minimal resistance. Lower slowly. Switch sides.

Sets: 4 per side. Reps: 15. Rest: 45 seconds between sides. Starting weight: 10 to 15 pounds. Progressive overload: add 2 to 3 pounds monthly. Common mistake: using hip lean or body momentum, if you must sway to lift the weight, reduce it.

Exercise 2: Dumbbell Lateral Raise (Drop Set)

Perform 10 reps at your working weight. Immediately drop to a lighter dumbbell, typically 2 to 4 pounds lighter, and perform 10 more reps without rest. This is a drop set: two consecutive sets at different weights with no rest between them. Drop sets extend the effective working volume beyond what a single weight allows and are particularly effective for smaller muscles like the lateral deltoid.

Sets: 3 drop sets. Reps: 10 heavy + 10 lighter. Rest: 90 seconds between drop sets. Common mistake: the drop weight being too close to the working weight, preventing additional reps.

Exercise 3: Machine Lateral Raise

On a lateral raise machine, position yourself so the pads rest on your forearms above your elbow. Set the seat height so your elbows align with your shoulder joint when your arms are at rest. Raise both arms simultaneously to shoulder height and hold for 1 second. Lower slowly. Machine lateral raises allow heavier loading than dumbbells and eliminate grip and momentum variables.

Sets: 3. Reps: 12. Rest: 60 seconds. Starting weight: machine-dependent, find a weight that makes rep 10 to 12 hard. Progressive overload: add one weight increment when all 3 sets of 12 are completed.

What should you expect at week 1, week 4 and week 12?

Week 4: Visible increase in shoulder width in photos.

Week 12: Clear lateral delt development visible in tank tops and bare-shoulder clothing. Waist-to-shoulder ratio measurably improved.

What should you read next?

Pair this with Slim shoulders training and Slim rear delts training, and see the high protein diet for Slim. To work with me, start with the XPL quiz, which is my intake form for every client and confirms whether Slim is your category, then see coaching options and pricing.

Written by Zavier King, personal trainer in Houston and online coach at XPL. ISSA Certified Personal Trainer and NASM Nutrition Coach.