This video covers Side-lying Sleeper Shoulder Internal Rotation (IR) PAILs/RAILs - a drill designed to improve shoulder IR range and, more importantly, your ability to control and tolerate that range under tension. Shoulder internal rotation matters for healthy overhead function, smoother pressing and pulling mechanics, comfortable reaching behind your back, and balanced shoulder mechanics over time. When IR is limited or poorly controlled, the body often compensates through the ribs, spine, or scapula, which can make shoulders feel tight, cranky, or unstable - especially with CrossFit-style volume, HYROX work, or heavy pressing.

The sequence (repeatable for sets or reps):
1. Passive stretch (~2 minutes): settle into the sleeper position and breathe, letting the shoulder adapt while you find a clean setup.
2. PAILs (progressive isometric contraction): gradually ramp tension into the position to create the intended stimulus for the day.
3. RAILs (regressive isometric contraction): reverse the intent and actively pull deeper into the newly available IR range with controlled effort.
4. Sink into the new range: ease off slightly and settle into the position you just earned.
5. Repeat for additional rounds if you’re doing multiple sets.

Programming note: The iso duration, intensity, and total time under tension should match your goal for the session - lighter/shorter for prep and patterning, heavier/longer for strength and adaptation.

Optional equipment: A yoga block to rest your head on for comfort and better alignment.