Plank Jack

Dynamic core cardio — combines plank stability with jumping jack motion for metabolic conditioning and hip strength

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⚡ Quick Reference

Aspect	Details
Pattern	Core Stability + Cardio
Primary Muscles	Core, Abs, Hip Abductors
Secondary Muscles	Shoulders, Glutes
Equipment	None (bodyweight)
Difficulty	⭐⭐ Intermediate
Priority	🟡 Supplementary

Movement Summary

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🎯 Setup

Starting Position

1. Position: Start in high plank position (top of push-up)
2. Hands: Directly under shoulders, fingers spread
3. Feet: Together or close together
4. Body line: Straight from head to heels
5. Core: Fully braced, glutes engaged
6. Head: Neutral, looking at floor slightly ahead
7. Weight: Balanced through hands and balls of feet

Setup Cue

"Perfect plank first — then add the jumping motion"

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🔄 Execution

The Movement

🔝 Starting Position

What's happening: Stable high plank with feet together

1. High plank with hands under shoulders
2. Feet together or touching
3. Body in straight line
4. Core fully engaged
5. Ready to jump

Feel: Whole body tight, core braced

⬅️➡️ Jump Out

What's happening: Jumping feet wide apart

1. Jump both feet out to sides simultaneously
2. Land with feet wider than hip-width
3. Keep hips level — don't let them pike up
4. Maintain straight body line
5. Core stays braced throughout jump

Tempo: Quick, explosive

Feel: Hip abductors working, core controlling position

➡️⬅️ Jump In

What's happening: Jumping feet back together

1. Jump both feet back to center
2. Land with feet together or touching
3. Keep body rigid — no sagging
4. Maintain plank position throughout
5. Core stays engaged

Tempo: Quick, rhythmic

Feel: Hip adductors engaging, cardio demand increasing

🔄 Rhythm

What's happening: Continuous alternating motion

1. Rhythmic out-in-out-in pattern
2. Maintain steady tempo
3. Breathe rhythmically (don't hold breath)
4. Keep hips stable and level
5. No bouncing or excessive movement in upper body

Common error here: Hips piking up or sagging down with each jump

Key Cues

Primary Cues

• "Jump light and quick" — stay on balls of feet
• "Hips stay level" — no piking or sagging
• "Plank the whole time" — upper body stays rigid
• "Breathe rhythmically" — don't hold breath

Tempo Guide

Goal	Cadence	Total Time	Rest
Cardio/HIIT	Fast (2 per second)	20-30s	10-20s
Endurance	Moderate (1 per second)	30-60s	30s
Strength-Endurance	Controlled	45-60s	45-60s

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💪 Muscles Worked

Activation Overview

Primary Movers

Muscle	Action	Activation
Rectus Abdominis	Anti-extension — maintains plank position	████████░░ 75%
Hip Abductors	Spreads legs apart during jump out	███████░░░ 70%

Secondary Muscles

Muscle	Action	Activation
Anterior Deltoid	Supports plank position	██████░░░░ 60%
Glutes	Prevents hip sag, assists with leg movement	██████░░░░ 55%
Hip Adductors	Brings legs together during jump in	██████░░░░ 55%

Stabilizers

Muscle	Role
Obliques	Anti-rotation and lateral stability
Hip Flexors	Maintains hip position
Serratus Anterior	Stabilizes shoulder blades

Unique Benefit

Dual training effect — combines isometric core stability with dynamic hip abduction/adduction and cardiovascular conditioning.

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⚠️ Common Mistakes

Mistake	What Happens	Why It's Bad	Fix
Hips piking up	Butt rises with each jump	Less core work, easier cheat	Brace core harder, slow down
Hips sagging	Lower back drops	Low back strain	Squeeze glutes, engage core
Landing heavy	Loud, hard landings	Joint stress, less control	Land softly on balls of feet
Upper body moving	Shoulders shifting around	Less stability work	Lock shoulders in place
Holding breath	Not breathing rhythmically	Fatigue faster, unsafe	Breathe in rhythm with jumps

Most Common Error

Hips piking up — when fatigued, hips rise to make it easier. This defeats the core stability purpose. Slow down or stop when form breaks.

Self-Check Checklist

• Hips stay level throughout (no piking or sagging)
• Body maintains straight line
• Landing softly on balls of feet
• Upper body stays stable and rigid
• Breathing rhythmically, not holding breath

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🔀 Variations

By Difficulty

Easier (Regressions)

Variation	How	When to Use
Step-Out Plank	Step feet out one at a time instead of jumping	Learning the pattern
Marching Plank	Alternate lifting one foot at a time	Building toward dynamic movement
Slow Plank Jack	Very slow, controlled jumps	Building control

Standard

Variation	How	Emphasis
Standard Pace	Moderate tempo (1 per second)	Balanced cardio and stability
Timed Sets	30-60 second intervals	Endurance focus
Rep-Based	Count reps (20-30)	Strength-endurance

Harder (Progressions)

Variation	How	When to Use
Fast Tempo	High speed for HIIT	Maximum cardio challenge
Plank Jack to Push-Up	Push-up after each jack	Combined upper body and core
Weighted Vest	Add weight vest	Increased difficulty

By Target

Target	Variation	Change
Cardio	Fast tempo, HIIT intervals	Speed and duration
Hip Strength	Slow, controlled tempo	Focus on muscle engagement
Core Endurance	Timed holds (60+ seconds)	Extended duration
Full Body	Plank Jack to Push-Up	Add upper body work

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📊 Programming

Rep Ranges by Goal

Goal	Sets	Reps or Time	Rest	Notes
Cardio/HIIT	3-5	20-30s	10-20s	Max intensity
Endurance	2-4	30-60s	30-45s	Sustained effort
Strength-Endurance	3-4	20-30 reps	45-60s	Controlled pace

Workout Placement

Program Type	Placement	Rationale
HIIT circuit	Station exercise	High-intensity cardio
Core workout	Dynamic finisher	After static core work
Warm-up	Movement prep	Light, gets heart rate up
Full body	Cardio bridge	Between strength exercises

Progression Scheme

How to Progress

Start with 20-30 second sets. When you can maintain perfect form (no hip piking) for 60+ seconds, increase speed or add variations like push-ups.

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🔄 Alternatives & Progressions

Exercise Progression Path

Regressions (Easier)

Exercise	When to Use
Step-Out Plank	Can't coordinate jumping yet
Marching Plank	Building core stability
Slow Plank Jack	Learning movement pattern

Progressions (Harder)

Exercise	When Ready
Fast Plank Jack	Standard is easy for 60s
Plank Jack to Push-Up	Want more upper body work
Burpee	Want maximum cardio challenge

Similar Dynamic Core Exercises

Alternative	When to Use
Mountain Climber	Want more running motion
High Knees	Pure cardio without plank hold
Jumping Jack	Traditional cardio alternative

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🛡️ Safety & Contraindications

Who Should Be Careful

Condition	Risk	Modification
Low back pain	Impact and sustained plank position	Reduce speed, regress to step-outs
Wrist pain	Weight on wrists	Use push-up handles or avoid
Hip issues	Repetitive abduction/adduction	Reduce range or avoid
High impact sensitivity	Joint stress from jumping	Use step-out variation

Stop Immediately If

• Sharp pain in lower back, hips, or wrists
• Inability to maintain plank position
• Dizziness or breathing difficulty

Safety Tips

• Master standard plank hold before attempting plank jacks
• Start slow — speed comes with practice
• Land softly on balls of feet, not heels
• Stop when hips start piking or sagging
• Keep movements controlled, not frantic

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🦴 Joints Involved

Joint	Action	ROM Required	Stress Level
Hip	Abduction/adduction (leg movement)	Moderate	🟡 Moderate
Core/Spine	Anti-extension stabilization	Isometric hold	🟡 Moderate
Shoulder	Stabilization in plank	Isometric hold	🟢 Low
Wrist	Extension (supporting weight)	~70-90°	🟡 Moderate

Joint-Friendly Approach

Land softly on balls of feet to minimize impact. If wrists hurt, use push-up handles or parallettes for neutral wrist position.

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❓ Common Questions

How wide should I jump my feet?

Jump feet slightly wider than hip-width — similar to a jumping jack stance. Going too wide increases hip pike risk.

Should I count reps or time?

For cardio/HIIT, use time (20-30s intervals). For strength-endurance, count reps (20-30). Both are effective for different goals.

My hips keep rising. How do I fix this?

Slow down significantly, focus on core bracing, or regress to step-out planks. Rising hips = core fatigue or going too fast.

Can I do this every day?

You can, but 3-4x per week is usually sufficient. If doing daily, vary intensity and duration to avoid overuse.

How is this different from mountain climbers?

Plank jacks move legs laterally (abduction/adduction), while mountain climbers bring knees forward (flexion). Both are great cardio, different movement patterns.

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📚 Sources

Biomechanics & Programming:

• ExRx.net — Tier C
• ACE Exercise Library — Tier B

Core Training & Cardio:

• NSCA Essentials — Tier A
• HIIT Training Protocols — Tier B

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For Mo

When to recommend this exercise:

• User wants bodyweight cardio with core component
• User needs HIIT workout exercises
• User wants dynamic core training
• User is looking for home cardio options

Who should NOT do this exercise:

• Acute low back injury → Wait for recovery
• Severe wrist pain → Avoid or modify
• Cannot hold standard plank for 30+ seconds → Regress first
• High impact restrictions → Use step-out variation

Key coaching cues to emphasize:

1. "Master plank hold first, then add movement"
2. "Hips stay level — don't let them pike up"
3. "Land softly, jump lightly"

Common issues to watch for in user feedback:

• "My hips go up" → Slow down, focus on core bracing, or regress
• "My wrists hurt" → Try push-up handles or reduce duration
• "I get out of breath fast" → Normal for cardio exercise, reduce pace

Programming guidance:

• For cardio: 3-5 sets of 20-30s with 10-20s rest
• For endurance: 2-4 sets of 30-60s with 30-45s rest
• Progress when: Can do 60s with perfect form (no hip pike)

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Last updated: December 2024