Cocoon Crunch

Cocoon Crunch trains the abdominal muscles by bringing the rib cage and pelvis closer together through a controlled range.

Primary muscle
Abs

Primary musclesRectus abdominis

Secondary musclesInternal and external obliques, Iliopsoas

Equipment
Bodyweight
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How to perform Cocoon Crunch

Follow the sequence in order, paying attention to the starting position, movement path, and finish described in each step.

  1. Lie long on the floor with the arms extended overhead and the legs straight without letting the lower back arch.

  2. Brace the abdomen, then lift the shoulders as the knees bend and travel toward the chest.

  3. Sweep the arms forward around the shins as the ribs and pelvis draw together into the compact cocoon position.

  4. Pause without pulling on the legs or rocking onto the neck.

  5. Extend the arms and legs away from one another under control, stopping before the lower back lifts.

Common Cocoon Crunch mistakes

Pulling on the neck

Support the head lightly or cross the arms; the abdominals should move the rib cage.

Using arm momentum

Keep the arms still and let the abdominal muscles move the rib cage toward the pelvis.

Moving through the hips only

Begin by bringing the ribs toward the pelvis rather than simply sitting upright with the hip flexors.

Dropping the return

Lower the spine or torso gradually and keep tension through the longest position.

When to modify or choose another exercise

  • Pulling on the neck: Support the head lightly or cross the arms; the abdominals should move the rib cage.
  • Moving through the hips only: Begin by bringing the ribs toward the pelvis rather than simply sitting upright with the hip flexors.
  • Stop when the exercise produces sharp, catching, radiating, or increasing joint pain rather than the expected muscular effort.
  • Alternative Short-range abdominal crunch: Lift only the head and shoulder blades while the pelvis and feet remain supported.

How to use Cocoon Crunch in a training program

01

Where it fits in a session

Place Cocoon Crunch after the main compound lifts, in a focused core block, or beside an exercise that does not require a fresh trunk.

02

How often to use it

Use two to four times per week while accounting for trunk work already supplied by squats, hinges, carries, and overhead lifting.

Starting rep ranges by goal

GoalSetsReps or timeRestEffort and execution
Control / technique2–35–8 reps45–75 secStop well before position changes
Strength / endurance2–48–15 reps60–90 secStop while 1–3 good-form reps are still possible

Pairing and sequencing

  • Use Cocoon Crunch after Barbell Back Squats, Deadlifts, or another main compound lift.
  • Pair it with Bird Dog or Cable Pallof Press to combine trunk flexion with stability work.

Regressions and progressions for Cocoon Crunch

Start with an easier option

Short-range abdominal crunch

Lift only the head and shoulder blades while the pelvis and feet remain supported.

Dead bug

Train abdominal bracing without repeated spinal flexion.

Progress when form is repeatable

Tempo Cocoon Crunch

Use a slow lowering phase and pause in the shortened position without pulling on the neck.

Loaded trunk flexion

Add a small load only after the full bodyweight range remains controlled.

References
  1. Mayo ClinicAbdominal Crunch Technique
  2. Mayo ClinicWeight Training: Do's and Don'ts of Proper Technique
  3. American College of Sports MedicineACSM Resistance Training Guidelines Update
  4. NHSHow to improve your strength and flexibility
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