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Hollow Body Rock

The gymnast's rhythm builder — takes the static hollow position and adds dynamic rocking to develop timing, coordination, and relentless core endurance

⚡ Quick Reference​

AspectDetails
PatternCore - Dynamic Anti-Extension
Primary MusclesCore, Rectus Abdominis
Secondary MusclesTransverse Abdominis, Obliques
StabilizersHip Flexors, Shoulders, Quads
EquipmentBodyweight (optional mat)
Difficulty⭐⭐⭐ Intermediate-Advanced
Priority🟡 Accessory

Movement Summary​

🎯 Setup​

Starting Position​

  1. Start supine: Lie on back on mat or floor
  2. Create hollow position: Posterior pelvic tilt, lower back pressed to floor
    • This is IDENTICAL to hollow body hold setup
    • Lower back completely flat, no arch
  3. Arm position: Arms extended overhead by ears
    • Biceps by temples
    • Shoulders protracted (pushed forward)
  4. Leg position: Both legs straight, together, hovering 6-12 inches off floor
    • Toes pointed
    • Legs squeezed together tight
  5. Head position: Slightly lifted, looking toward toes
  6. Body shape: Tight "banana" or "rocker" shape from hands to toes
  7. Total tension: Everything squeezed tight before first rock

Equipment Setup​

EquipmentSettingNotes
MatOptionalProtects tailbone/upper back during rocking
Floor SpaceClear areaNeed room to rock without hitting obstacles
Towel (head)OptionalSome people prefer padding under head
Setup Cue

"Exact same hollow body position as the static hold, but now you're a rocking chair — locked into that banana shape, ready to rock back and forth"

Key Difference from Hollow Hold​

AspectHollow HoldHollow Rock
MovementStatic — no movementDynamic — rocking motion
DifficultyBuild to this firstProgress to this second
DurationLonger holds (30-60s)Continuous rocking (20-60s or 10-30 rocks)
FocusPosition masteryRhythm and coordination

🔄 Execution​

The Movement​

What's happening: Building the static hollow before adding rocks

  1. Lie flat, press lower back into floor (posterior pelvic tilt)
  2. Extend arms overhead, keeping back down
  3. Lift legs straight, hovering low (6-12 inches)
  4. Create maximum tension — banana shape
  5. Hold this position for 5-10 seconds to verify form
  6. If back lifts at any point, raise legs higher

Critical: You must be able to hold a clean hollow position for 30s+ before attempting rocks

Feel: Total core engagement, everything tight

Key Cues​

Primary Cues
  • "Lock into hollow position — never break the banana shape" — maintain form throughout
  • "Small smooth rocks — like a rocking chair" — controlled rhythm, not wild swings
  • "Press through shoulders back, press through hips forward" — initiate rocks from core
  • "Lower back glued to floor — never loses contact" — the non-negotiable rule

Duration & Rep Guide​

LevelDuration/RepsSetsRest
Beginner10 rocks or 15-20s3-460-90s
Intermediate20 rocks or 30-40s3-560s
Advanced30+ rocks or 45-60s4-590s

💪 Muscles Worked​

Activation Overview​

Primary Movers​

MuscleActionActivation
Rectus AbdominisAnti-extension + dynamic control during rocks██████████ 95%
Transverse AbdominisDeep stabilization, maintain compression█████████░ 90%

Secondary Muscles​

MuscleActionActivation
ObliquesPrevent rotation during rocking, assist stability███████░░░ 75%
Hip FlexorsMaintain leg position, assist with rocking motion████████░░ 80%

Stabilizers​

MuscleRole
QuadricepsKeep legs straight and engaged
Shoulders/SerratusHold arms overhead, assist rocking
AdductorsKeep legs together tightly
GlutesAssist pelvic tilt, prevent hyperextension
Dynamic vs. Static Hollow

Hollow Body Hold (Static):

  • Pure isometric strength
  • Position mastery
  • Longer duration capability
  • Less cardiovascular demand

Hollow Body Rock (Dynamic):

  • Adds coordination and rhythm
  • More metabolically demanding
  • Builds dynamic core control
  • Transfers better to kipping movements (gymnastics)

Both are valuable. Master the hold before adding rocks.

⚠️ Common Mistakes​

MistakeWhat HappensWhy It's BadFix
Breaking hollow position to rock biggerBody opens up, back archesDefeats entire purpose, dangerousKeep hollow perfect, rock smaller
Rocking too violentlyHuge swings, loss of controlMomentum-based, not strength-basedSmall controlled rocks, 6-12" range
Lower back archingSpinal extension occurs during rockingDangerous for lower backRaise legs higher, reduce rock amplitude
Throwing arms/legsUsing limbs to generate momentumReduces core engagementKeep limbs fixed in hollow position, rock from core
Head banging floorHitting head during backward rockUncomfortable, unsafeLift head slightly more, add padding, or reduce rock
Stopping between rocksLosing continuous flowReduces endurance benefitMaintain rhythm, continuous flow
Holding breath entire setNo breathingUnsustainable, blood pressure spikeShallow continuous breathing
Most Common Error

Breaking the hollow body position to achieve bigger rocks — the entire point is to MAINTAIN perfect hollow position while rocking. If you have to break position to rock, you're rocking too big. Rock smaller with perfect form.

Self-Check Checklist​

  • Lower back never arches (stays pressed to floor throughout)
  • Body maintains banana/rocker shape (no opening up)
  • Arms stay overhead by ears (not moving relative to torso)
  • Legs stay straight, together, at consistent height
  • Smooth rhythmic rocking (not jerky or violent)
  • Continuous breathing (not holding breath)
  • Can maintain for target duration or reps

🔀 Variations​

By Difficulty​

VariationChangeWhy EasierWhen to Use
Tuck Hollow RocksKnees bent to chestShortest lever armsLearning the rocking motion
Single Leg RocksOne leg bent, one extendedHalf difficultyTransition from tuck to full
Arms at Sides RocksArms down by sidesRemoves overhead componentShoulder mobility limitations
Higher Leg RocksLegs at 45° angleLess core challengeBuilding endurance first
Static Hollow HoldNo rocking, just holdRemoves dynamic componentNot ready for rocks yet

By Position Modification​

PositionDifficultyWhen to Use
Arms OverheadHardestStandard position
Arms by Ears, LowerHardSlight reduction if shoulders tight
Arms Extended ForwardModerateEasier overhead alternative
Arms at SidesEasiestShoulder limitations or learning

Scaling Decision Tree​

📊 Programming​

Duration/Rep Ranges by Goal​

GoalSetsDuration/RepsRestNotes
Learning/Coordination3-410 rocks or 15s60-90sFocus on rhythm and form
Endurance3-520-30 rocks or 40-60s60sContinuous flow
Strength-Endurance4-515-20 rocks or 30-45s90sLegs very low, weighted
Skill Work5-610-15 rocks60sSub-maximal, frequent practice

Workout Placement​

Program TypePlacementRationale
Gymnastics/BodyweightEarly (after warmup)Skill work when fresh
Core-focusedBeginning or middleDemanding but can be repeated
WarmupAfter general warmupPrime hollow position for training
FinisherEndExhaust core after main work
Skill practiceStandaloneDaily practice for rhythm mastery

Frequency​

Training LevelFrequencyVolume Per Session
Beginner (to rocks)3-4x/week3-4 sets x 10-15 rocks
Intermediate3-5x/week3-5 sets x 20-25 rocks
Advanced4-6x/week4-5 sets x 30+ rocks or weighted

Progression Scheme​

Progressive Overload for Hollow Rocks

Progress by:

  1. Increasing reps/duration — build from 10 to 30+ rocks per set
  2. Lowering limbs — legs from 12" to 6" to 3" off floor
  3. Adding sets — increase from 3 to 5 sets
  4. Decreasing rest — reduce from 90s to 60s
  5. Harder variation — tuck → single leg → full → hollow-to-arch
  6. Adding weight — light plate on chest (2.5-5 lbs)

Never sacrifice form for more reps. Quality > quantity always.

Sample 6-Week Progression​

WeekVariationTargetFocus
1-2Full Hollow Rocks3x10-15Learn rhythm, maintain hollow
3-4Full Hollow Rocks3x20-25Build endurance
5-6Lower Leg Rocks or Weighted3x15-20Increase difficulty

🔄 Alternatives & Progressions​

Exercise Progression Path​

Regressions (Easier)​

ExerciseWhen to UseLink
Hollow Body HoldCannot maintain hollow while rockingLink
Tuck Hollow RocksFull extension too challenging
Single Leg Hollow RocksBuilding from tuck to full
Arms at Sides Hollow RocksShoulder mobility limitation

Progressions (Harder)​

ExerciseWhen ReadyLink
Weighted Hollow RocksCan do 30+ perfect rocks
Hollow to Arch RocksMastered hollow rocks, want dynamic bodyline
Hollow Rocks to CandlestickAdvanced gymnastic skills
Dragon FlagElite core progressionLink

Alternatives (Same Goal, Different Movement)​

AlternativePositionGood For
Dead BugSupine, alternatingLearning anti-extension pattern
V-UpSupine, foldingDynamic core flexion
Superman RocksProne, opposite of hollowArch position practice
Ab Wheel RolloutKneeling/standingDynamic anti-extension

🛡️ Safety & Contraindications​

Who Should Be Careful​

ConditionRiskModification
Lower back painRocking may aggravate if form breaksStart with hollow holds, ensure perfect position
Hip flexor strainHolding legs extended creates tensionRaise legs higher, reduce duration
Neck painRocking can cause head to bump floorMore head lift, padding under head, or avoid
Pregnancy (all trimesters)Supine position contraindicated 2nd/3rdAvoid after 12-16 weeks
Tailbone sensitivityRocking directly on tailboneExtra padding (mat or towel)
Stop Immediately If
  • Sharp pain in lower back (sign of arching)
  • Head hitting floor hard repeatedly
  • Hip flexor sharp pain or cramping
  • Neck strain or pain
  • Dizziness (especially pregnant women)
  • Lower back uncontrollably arching despite efforts

Safe Execution​

Best practices for hollow rock safety:

  1. Master hollow hold first: 30s minimum before attempting rocks
  2. Start with small rocks: 3-6 inches initially, build amplitude gradually
  3. Use padding: Mat or towel to protect tailbone and back
  4. Never sacrifice hollow position: Rock smaller to maintain form
  5. Progress conservatively: Add 2-5 reps per week, not per workout
  6. Listen to your body: Discomfort is normal, pain is not

Head & Neck Safety​

Rocking can cause head bumping issues:

  • Lift head more — keep head off floor throughout
  • Add padding — towel or small pad under head
  • Control rocks — don't rock so violently head slams down
  • Check neck position — neutral, not craned forward excessively

If neck hurts or head bumping persists, stick with hollow holds instead.

Lower Back Considerations​

The rocking motion can reveal lower back weakness:

  • Form breaks during rocks = back arches — this is dangerous
  • If back arches, STOP — regress to hollow holds or easier variation
  • Build gradually — rocks are harder than holds for most people
  • Posterior pelvic tilt is key — maintain throughout every rock

Tailbone Discomfort​

Some people experience tailbone pressure:

  • Add padding — thick mat, folded towel, or yoga mat
  • Reduce rock amplitude — smaller rocks = less pressure
  • Modify position — slightly higher leg position may help
  • Alternative: If persistent, do hollow holds instead
Reality Check

Hollow rocks are HARDER than hollow holds for most people because:

  • Maintaining position while moving requires more control
  • Rocking creates dynamic challenge to stability
  • Endurance is tested more (continuous motion)
  • Coordination and rhythm must be learned

Don't rush to rocks. Mastering the hold is essential first.

🦴 Joints Involved​

JointActionROM RequiredStress Level
SpineStability in posterior pelvic tiltSlight flexion (rounded)🟡 Moderate
HipFlexion (holding legs up)~30-45° flexion🟡 Moderate
ShoulderFlexion overhead~180° flexion🟡 Moderate

Mobility Requirements​

JointMinimum ROMTestIf Limited
Shoulder180° flexionCan reach arms overhead flat against wallKeep arms at 45° or by sides
Hip90° flexion capabilityCan lie flat with legs at 45°Adequate for most people
Thoracic SpineFlexion capabilityCan round upper backUsually fine
Joint-Friendly Exercise

Hollow rocks are generally very safe for joints when done with proper form:

  • Spinal safety: Maintained in safe flexed position (not extended)
  • Shoulder safety: No load-bearing, just overhead position
  • Hip safety: Natural ROM, no extreme positions

Main risk: Breaking hollow position and allowing lower back to arch (hyperextension). This is form error, not inherent joint risk.

❓ Common Questions​

How is this different from just doing hollow holds?

Key differences:

AspectHollow HoldHollow Rock
MovementStatic/isometricDynamic rocking
ChallengePure strength enduranceStrength + coordination
DurationTypically longer (45-60s)Typically shorter (20-40s) but more intense
SkillPosition masteryRhythm and flow
TransferGeneral core strengthKipping movements, gymnastics timing

When to use each:

  • Hollow hold: Building foundation, strength focus, longer duration capacity
  • Hollow rock: Adding variety, coordination, gymnastic prep, metabolic challenge

Both are valuable. Do both.

I can hold a hollow position but can't rock. Why?

Common reasons:

1. Not pressing hard enough to initiate rock:

  • Solution: Push HARD through upper back/shoulders to rock backward
  • Push through glutes/hips to rock forward
  • Start with TINY rocks (2-3 inches)

2. Breaking position to try to rock:

  • Solution: Keep hollow PERFECT, rock smaller
  • The rock happens FROM the hollow position, not instead of it

3. Floor is too soft/grippy:

  • Solution: Try on firmer surface (wood floor vs. thick carpet)
  • Thin yoga mat on hard floor is ideal

4. Not enough momentum to get started:

  • Solution: Small deliberate press backward to start the first rock
  • Once rocking starts, momentum helps maintain
My head keeps hitting the floor. What should I do?

Several solutions:

Immediate fixes:

  1. Lift head more — keep chin more tucked, head off floor throughout
  2. Add padding — towel or thin pillow under head area
  3. Rock smaller — reduce amplitude of backward rock
  4. Control the rock — slower, more controlled backward motion

Long-term:

  • Build neck strength to hold head position better
  • Practice hollow holds with head lifted more
  • Consider that rocks might not be right for you — holds work just as well

Safety: If head banging persists despite these fixes, stick with hollow holds instead. Not everyone needs to do rocks.

Should I count reps or time?

Both work — choose based on goal and preference:

Count reps (rocks) when:

  • You want clear progression tracking (10 rocks → 15 rocks → 20 rocks)
  • Doing lower rep strength work
  • You prefer counting to timers

Count time when:

  • Building endurance is the goal
  • You want to match your hollow hold practice
  • You prefer timed intervals

Typical equivalents:

  • 10 rocks ≈ 15-20 seconds
  • 20 rocks ≈ 30-40 seconds
  • 30 rocks ≈ 45-60 seconds

Recommendation: Pick one method and stick with it for a training block (4-8 weeks) for consistent tracking.

Can I do hollow rocks every day?

Yes, with caveats:

Safe for daily practice if:

  • Treating as skill/movement work, not max effort grind
  • Doing moderate volume (3-4 sets of 15-20 rocks)
  • Maintaining perfect form (never breaking hollow)
  • No pain or excessive fatigue
  • Balancing with other core work

Not recommended daily if:

  • Going to absolute failure every session
  • Experiencing hip flexor pain that doesn't resolve
  • Already doing very high volume core work
  • Form breaks down due to fatigue

Suggested approach:

  • 3-4 days: More intense hollow rock work (4-5 sets, higher reps)
  • 2-3 days: Light practice (2-3 sets, moderate reps, focus on quality)
  • 1-2 days: Rest or different core work

Many gymnasts practice hollow rocks 5-6 days per week as foundational movement patterning.

What's the difference between hollow rocks and "banana rolls"?

They're essentially the same movement with different names:

  • Hollow rocks — common in gymnastics, CrossFit, bodyweight training
  • Banana rolls — sometimes used in Pilates or other disciplines
  • Rocker holds — another term for the same movement

All refer to: maintaining hollow body position while rocking back and forth.

Note: Some people use "hollow rocks" to mean ONLY the rocking motion, while "hollow body rocks" might include the full sequence of hollow hold → rocks → back to hold. But generally these terms are interchangeable.

I feel this way more in hip flexors than abs. Normal?

Somewhat normal, but should feel BOTH significantly:

If hip flexors dominate:

  • Legs might be too low → raise them higher
  • Not enough posterior pelvic tilt → focus on tucking tailbone
  • Core not engaged enough → brace abs harder before and during rocks

Proper feel:

  • Hip flexors: 70-80% — yes, they work hard holding legs
  • Abs/core: 85-95% — should be burning intensely

Tips to increase ab engagement:

  • Think "pulling knees toward chest" even though legs are straight
  • Exhale hard and brace abs maximally
  • Press lower back INTO floor actively throughout

As you get stronger, the feeling balances out more. But hip flexor involvement is expected and normal in hollow work.

📚 Sources​

Biomechanics & Muscle Activation:

  • McGill, S.M. (2010). Core Training: Evidence Translating to Better Performance — Tier A
  • Sommer, C. Gymnastic Bodies Curriculum — Core Bodyline Development — Tier B
  • Kavcic, N., Grenier, S., & McGill, S.M. (2004). Determining the stabilizing role of individual torso muscles — Tier A

Programming & Gymnastics:

  • USA Gymnastics Training Methodology — Foundational Movements — Tier A
  • Sommer, C. (2008). Building the Gymnastic Body — Tier B
  • CrossFit Journal — Hollow Position and Gymnastics Skills — Tier C

Technique & Coaching:

  • Gymnastic conditioning research and practice — Tier B
  • Physical therapy applications of hollow body positioning — Tier B
  • Coach Sommer's Forum — Hollow Rock Progressions — Tier C

Movement Science:

  • NSCA Essentials of Strength Training and Conditioning — Core Training — Tier A
  • Functional Movement Systems — Bodyline Control — Tier B
For Mo

When to recommend this exercise:

  • User has mastered hollow body hold (30s+) and wants progression
  • User wants to build rhythmic core control and coordination
  • User has gymnastics goals (kipping, bar work, tumbling)
  • User wants variety from static hollow holds
  • User is preparing for kipping movements (pull-ups, toes-to-bar)

Who should NOT do this exercise:

  • Cannot hold hollow position for 30s → Start with Hollow Body Hold
  • Pregnant (2nd/3rd trimester) → Avoid supine positions
  • Severe neck issues or head repeatedly banging floor despite modifications → Stick with hollow holds
  • Acute lower back pain → Too advanced, use Dead Bug or Plank
  • Cannot maintain hollow position when attempting to rock → Not ready, build static hold first

Key coaching cues to emphasize:

  1. "Maintain perfect hollow position — never break the banana shape to rock bigger"
  2. "Small smooth rocks — like a rocking chair, not wild swinging"
  3. "Lower back stays glued to the floor throughout every rock"
  4. "Rock from your core — press through shoulders back, press through hips forward"

Common issues to watch for in user feedback:

  • "Can't rock at all" → Press harder through upper back to initiate, start with tiny rocks, check floor surface
  • "My back arches when rocking" → Not ready for rocks, keep practicing hollow holds, or raise legs higher
  • "Head keeps hitting floor" → Lift head more, add padding, rock smaller, or stick with holds
  • "Feel it all in hip flexors" → Normal but focus on posterior pelvic tilt and core bracing
  • "Losing rhythm/stuttering" → Slow down, find natural cadence, count "1-2, 1-2"

Programming guidance:

  • Pair with: Gymnastics training, kipping practice, other core work, skill development
  • Great for: Warmup, core finisher, skill work, gymnastics prep, daily practice
  • Typical frequency: 3-5x per week, can be daily if sub-maximal
  • Volume: 3-5 sets of 15-30 rocks (or 20-60s continuous)
  • Place early in workout for skill work, or as finisher for metabolic challenge

Progression signals:

  • Ready to progress when: Can do 30+ perfect rocks maintaining hollow position, no back arching
  • Regress if: Cannot maintain hollow position while rocking, back arches, form breaks down
  • Plateau solution: Lower legs closer to floor, add weight, or progress to hollow-to-arch rocks

Alternative recommendations based on feedback:

  • "Too hard" → Hollow Body Hold, tuck hollow rocks, single leg rocks
  • "Too easy" → Lower legs to 3-6", weighted hollow rocks, hollow-to-arch rocks
  • "Head bumping issue" → Add padding, lift head more, or stick with static holds
  • "Want gymnastics skill transfer" → Perfect choice, pair with kipping practice and arch rocks
  • "Boring" → Add variety: hollow-to-arch rocks, timed challenges, EMOM format

Special notes:

  • Hollow rocks are FUNDAMENTAL in gymnastics for developing kipping timing
  • Dynamic version is often harder than static holds — set expectations
  • Quality over quantity ALWAYS — perfect hollow position is non-negotiable
  • Excellent for building coordination and body awareness, not just strength
  • Transfers directly to: kipping pull-ups, kipping toes-to-bar, tumbling, bar skills
  • Can be practiced as daily movement prep (greasing the groove)
  • The rhythmic nature can be meditative — some people find these more enjoyable than static holds
  • Great metabolic finisher — 3-5 minutes of continuous hollow rocks is BRUTAL

Red flags requiring immediate regression:

  • Lower back arching uncontrollably during rocks
  • Head banging floor hard despite modifications
  • Severe hip flexor cramping or pain
  • Complete inability to achieve rocking motion (indicates not ready)
  • Pain beyond normal muscle fatigue

Last updated: December 2024