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  7. Rainbow Side Plank

Exercise guide

Rainbow Side Plank

  • Intermediate
  • Compound
  • Timed hold
  • Shoulders
  • Waist

The Rainbow Side Plank is a dynamic core exercise that enhances lateral stability and oblique strength by adding a vertical hip arc to a traditional side plank. It simultaneously challenges shoulder stability and the entire kinetic chain of the torso.

Reviewed by the Crucible team · Updated June 2026

Watch the Rainbow Side Plank demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Abs
  • Deltoids
  • Obliques
  • Pectorals

Secondary

  • Rhomboids
  • Serratus anterior
  • Trapezius

Equipment

  • Body weight

Setup

  1. Lie on your side and prop yourself up on your forearm, ensuring the elbow is directly beneath the shoulder.
  2. Stack your feet on top of each other or stagger them (top foot in front) for better balance.
  3. Lift your hips to create a straight line from your head to your heels, placing your top hand on your hip.

How to do it

  1. Inhale and slowly lower your bottom hip toward the floor in a controlled manner without touching the ground.
  2. Exhale and drive through your forearm to lift your hips as high as possible, forming an arch shape.
  3. Maintain a steady tempo of 2 seconds down and 1 second up.
  4. Complete the set on one side before switching to the opposite side.

Form checklist

  • Keep the supporting elbow stacked directly under the shoulder to avoid joint strain.
  • Ensure your chest remains open and your shoulders stay stacked vertically.
  • Keep your glutes engaged to prevent your hips from drifting backward.
  • Maintain a neutral neck by looking straight ahead rather than at your feet.

Pro tips

  • Think about pulling your bottom ribs toward your hip bone at the peak of the movement to maximize oblique contraction.
  • Actively push the floor away with your forearm to engage the serratus anterior and stabilize the shoulder blade.

Make it harder

  • Extend your top arm toward the ceiling while holding a light dumbbell.
  • Perform the hip dip while keeping the top leg lifted in a 'star' position.

Frequently asked

What muscles does the rainbow side plank work?
The rainbow side plank primarily targets the abs, deltoids, obliques, and pectorals, and also works the rhomboids, serratus anterior, and trapezius as secondary muscles.
What equipment do you need for the rainbow side plank?
The rainbow side plank requires no equipment — just your body weight.
Is the rainbow side plank good for beginners?
The rainbow side plank is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals
  • Alternate Leg Lift Tap Arms CircleIntermediate · abs, deltoids, obliques, and pectorals
  • Battling Ropes Half KneelingIntermediate · abs, biceps, deltoids, obliques, and pectorals
  • Bear WalkIntermediate · abs, calves, deltoids, hamstrings, obliques, and pectorals

Train this with a plan, not guesswork

Crucible builds the rainbow side plank into a precise program around your body, equipment, location, and time.

Download on the App Store