HORIZON CORE | Week 4: Scapular Lock

Amy Petersen headshot
Amy Petersen
ACE-CPT, Sports Performance, PN-1, PATHFINDER Founder & Director of Programming
October 31, 2025

If your shoulders cave, your lungs follow and lessen how much oxygen you get.

This session targets the serratus, lats, and lower traps -- the muscles that hold your shoulder blades where they belong when a ruck starts pulling you forward. More scap control means better posture, better breathing, and more efficiency on every step.

Strong scaps don’t just help you carry the weight, they help you breathe under it.

Why this matters: Your serratus, lower traps, and lat muscles keep the ruck straps from folding your chest. Better scap control equals better breathing under load.

NOTES

  • RPE (rate of perceived exertion) should be 6
  • Belly breathing, including breathing into the back of the ribs, is useful for this workout. More info on belly breathing.
  • If needed, adjust the number of reps, time, or rounds to fit your fitness level.
  • If needed, rest 1-2 minutes between rounds.
  • Always do your warm-up to help prevent injuries.
  • Some video demonstrations may depict exercise tools other than a ruck - the same cues and form will still apply unless otherwise noted.

REMINDER:

  • Soft count: 1, 2, 3, 4 ... this is when both (or all) limbs perform the exercise at the same time.
  • Hard count: 1,1, 2, 2, 3, 3, 4, 4...this is when only one limb does work at a time.
  • Each Side: Do all reps on one side before switching to complete all reps on the other side.

WARM UP x 2 ROUNDS

 REPS EXERCISE COUNT
8 x Wall Slides
8 x Scapular Push-Ups (slow reps)

WORKOUT x 3 ROUNDS

 REPS EXERCISE COUNT
8 x Prone Y-T-W (strict form)
:30 sec x Ruck Overhead Hold, Supine
8 x KB Sit-Up to Overhead*
10 x DB/KB Lawnmower Row EACH SIDE
10 x Dead Bug with Chest Press

*Holding one KB at your preferred weight is recommended to start.