The reason it matters is mechanical. A freediver descending past 10 meters is compressing the lungs and rib cage against the pressure of the surrounding water. At 20 meters, lung volume is half what it was at the surface. At 30 meters, it's a third. A rib cage that can't yield gracefully under that compression generates more stress, harder squeeze risk, and — at depth — more anxiety. A rib cage that has been trained to expand and compress smoothly gives you a wider range of safe motion before any of those become problems.
This guide is a four-week stretching plan modeled after the structure Gert Leroy lays out in his book Stretching For Freediving: A 4-Week Beginner's Training Plan to Increase Flexibility, Dive Deeper & Hold Your Breath Longer (2020), adapted for the specific demands of an AIDA 2 student preparing for first depth dives. Twenty minutes a day, no equipment beyond a yoga mat, four weeks. It pairs with our 4-week AIDA 2 prep plan — run them in parallel.
What you're actually stretching, and why
Five tissue systems matter for freediving. Each one gets a focus in this protocol:
1. Intercostals and serratus anterior
These are the muscles between and around your ribs. They allow your rib cage to expand during a full inhale and yield without pain during descent. Tight intercostals limit the depth of your relaxation breath and make compression at depth feel sharper. This is the single highest-leverage area for a beginner freediver.
2. Thoracic spine
The middle and upper back. A stiff thoracic spine restricts rib motion no matter how much you stretch the intercostals directly. Most adults — especially anyone who works at a desk — have functionally fused thoracic mobility. Loosening it gives you both better lung volume and better head-down body position on a line.
3. Hip flexors and adductors
For finning efficiency. A tight hip flexor pulls the knee forward on every kick, fighting the streamlined position. Tight adductors make the kick narrow and inefficient. Open hips mean less work to move the same distance, which means less oxygen consumption, which means longer dive times.
4. Shoulder external rotation and lat length
For streamlining the arms overhead. Without it, your duck dive looks like a clothespin instead of a torpedo, and you arrive at depth in a position that wastes energy. Open shoulders also make the descent feel less like work.
5. Neck, jaw, and soft palate
The unglamorous one. Equalization happens through small movements in the back of the mouth and pharynx. Tight jaw muscles and a stiff neck make those movements feel forced. Releasing them is one of the cheapest ways to improve equalization for a struggling student.
Week 1 — Rib cage and breath awareness
The point of week 1 is to wake up tissues most students have never consciously moved. Twenty minutes a day, every day. Treat each stretch as 60–90 seconds of slow exploration, not a hold-and-grunt.
Daily routine (~20 min)
- Diaphragmatic breathing on the floor (5 min). Lie on your back, knees bent, hand on belly. Inhale for 4 counts into the belly only — chest stays still. Exhale for 8. This is the foundation; without it, none of the stretches matter as much.
- Side-bend ribstretch (3 min each side). Standing, reach one arm overhead and bend sideways, keeping hips square. Feel the stretch along the rib cage of the raised-arm side. Breathe into the stretched side specifically — your hand on the ribs should feel them expand under the skin.
- Cat-cow on hands and knees (3 min). Slow flexion and extension of the spine, segment by segment. Don't rush. Each pass should take 8–10 seconds.
- Supine chest opener (3 min). Lie on your back with a rolled towel running lengthwise under your spine, arms out in a T. Just lie there. Breathe.
- Child's pose with arms reaching forward (3 min). Sit on heels, fold forward, walk hands out as far as they go. Lats and shoulders.
By the end of week 1, you should be able to feel where your ribs move when you breathe. Most beginners can't.
Week 2 — Thoracic spine and shoulder mobility
Week 2 adds rotation and shoulder work on top of week 1. Keep doing week 1's diaphragmatic breathing daily; replace some of the rib work with the additions below.
Daily routine (~20–25 min)
- Diaphragmatic breathing (5 min). Continue daily.
- Thoracic rotation in child's pose, "thread the needle" (3 min each side). From child's pose, reach one arm under the other and across, lowering shoulder toward the floor. Look toward the ceiling. Slow.
- Open book stretch on the side (3 min each side). Lie on your side, knees bent at 90 degrees, arms outstretched in front of you. Slowly rotate the top arm over and back, opening the chest. Eyes follow the hand. This is the single best thoracic mobility stretch.
- Shoulder external rotation against a wall (2 min each side). Forearm vertical against a doorframe, slowly rotate the body away from the wall. Stretches the front of the shoulder.
- Lat stretch hanging from a doorframe or pull-up bar (2 min). Just hang. Let gravity decompress the spine and lengthen the lats.
- Side-bend ribstretch (2 min each side). Carry over from week 1.
Week 3 — Hips, hamstrings, and finning efficiency
Week 3 shifts attention to the lower half of the body. This is where finning efficiency comes from, and the most common deficit in adult beginners is hip flexor length. Continue diaphragmatic breathing daily.
Daily routine (~25 min)
- Diaphragmatic breathing (5 min). Daily.
- Couch stretch / kneeling hip flexor (3 min each side). Kneel with one knee on the ground, the back foot up against a wall or couch. Square the hips and press the pelvis forward. This is the gold standard for hip flexor length.
- Pigeon pose (3 min each side). External rotation of the front hip, length on the back hip. Don't force the depth — let it settle.
- Frog stretch (3 min). On hands and knees, knees wide, ankles in line with knees. Sit hips back and breathe.
- Hamstring stretch lying on the back (2 min each side). Use a towel or strap around the foot to keep the leg straight without rounding the lower back.
- Standing forward fold (2 min). Hang. Don't try to touch your toes — just let the spine decompress.
- Open book stretch (2 min each side). Carry over from week 2.
If you do nothing else in week 3, do the couch stretch every day. Adult hip flexors get tight from sitting and don't open back up on their own.
Week 4 — Equalization, jaw, and integration
The final week brings in the small, specific work that most freedivers skip: the jaw, neck, and soft palate. This is where you'll feel the most direct impact on equalization. Continue daily breathing and rotate the lower-body and rib work from previous weeks.
Daily routine (~25 min)
- Diaphragmatic breathing (5 min). Daily.
- Jaw release (3 min). Sit. Open the mouth wide and yawn deliberately. Massage the jaw joint (where you feel a hinge when you chew) with fingertips. Slow circles, both sides. Then relax the tongue against the floor of the mouth. Most adults carry chronic tension here without knowing it.
- Neck side-bends (2 min each side). Slowly tilt the ear toward the shoulder, then forward toward the chest, then back toward the shoulder blade. Slow circles. Don't grind.
- Soft palate K-T isolation (3 min). The dry Frenzel drill from our equalization guide. Practice the K-sound to engage the soft palate, then the T-sound to engage the tongue tip. Combine. This is the foundation of Frenzel equalization.
- Open book stretch (2 min each side). Always-on.
- Couch stretch (2 min each side). Always-on.
- Cat-cow + thread the needle (5 min). Flow through these as a full thoracic warm-down.
- Final relaxation on your back (3 min). Just lie there. Breathe diaphragmatically. Notice what's different.
How this plays out in the water
A student who has done four weeks of this protocol arrives at their first AIDA 2 course session with three observable changes:
- The relaxation breath gets deeper. The rib cage moves more freely, the diaphragm has been trained, and the "one full breath" before a dive actually reaches the bottom of the lungs.
- The duck dive looks cleaner. Open shoulders and a mobile thoracic spine mean the body folds into the descent position without forcing.
- Equalization feels less effortful. Released jaw and trained K-T isolation make the tongue movement more available.
None of these are dramatic on their own. Together, they're the difference between a student who looks coordinated in the water on day one and a student who looks like they're fighting the basic mechanics of their own body.
What this protocol is not
It's not a yoga class. It's not strength training. It's not designed to build flexibility for its own sake. Every stretch in here is here because of a specific mechanical demand of breath-hold diving — rib compression at depth, finning efficiency on the descent, mouth and palate control for equalization.
If you're already an experienced yoga practitioner, treat this as a supplementary protocol layered on top of your existing practice. If you've never stretched seriously, treat it as a foundation. Either way, twenty minutes a day for four weeks is enough to feel real changes in the water.
Sources and further reading
- Leroy, Gert. Stretching For Freediving: A 4-Week Beginner's Training Plan to Increase Flexibility, Dive Deeper & Hold Your Breath Longer. 2020. The book this protocol is anchored in.
- Pelizzari, Umberto. Manual of Freediving: Underwater on a Single Breath. Idelson Gnocchi Publishing, 2004. The classic reference, with stretching framed as part of the broader athletic preparation.
- LJFC: 4-Week AIDA 2 Prep Plan — run this stretching protocol in parallel for the full preparation.
- LJFC: Complete Guide to Equalization — the soft palate work in week 4 is anchored in this guide's Frenzel mechanics.
