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  7. Side Step Rainbow Arms

Exercise guide

Side Step Rainbow Arms

  • Intermediate
  • Compound
  • Rep-based
  • Shoulders
  • Upper arms

This dynamic compound movement combines a lateral step with a large overhead arm arc to engage the core, shoulders, and lower body simultaneously. It improves coordination and lateral stability while targeting the quads, deltoids, and chest through a fluid, rhythmic motion.

Reviewed by the Crucible team · Updated June 2026

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

Muscles worked

Primary

  • Calves
  • Quadriceps

Secondary

  • Serratus anterior
  • Trapezius

Equipment

  • Body weight

Setup

  1. Stand upright with feet hip-width apart, positioned to the side of a low step or platform.
  2. Keep your arms relaxed at your sides and maintain a neutral spine with shoulders pulled back.
  3. Engage your core and keep your gaze forward to prepare for the lateral movement.

How to do it

  1. Step one foot laterally onto the center of the step, bending the knee slightly into a shallow lunge while keeping the trailing leg straight.
  2. Simultaneously sweep both arms out to the sides and overhead in a large 'rainbow' arc, exhaling as your hands meet at the top.
  3. Inhale as you push firmly off the step to return to the starting position, lowering your arms back to your sides with control.
  4. Repeat the movement by stepping with the opposite foot, alternating sides with a steady, fluid tempo.

Form checklist

  • Keep your chest lifted and avoid leaning your torso too far forward during the step.
  • Ensure the knee of the stepping leg stays aligned with your toes and does not cave inward.
  • Maintain a tight core to prevent your lower back from arching as your arms reach overhead.
  • Land with your full foot on the step to ensure stability and proper calf engagement.

Pro tips

  • Focus on a full, wide range of motion with the arms to maximize engagement of the deltoids and pectorals.
  • Imagine 'pushing the step away' with your foot to increase the explosive power and activation of the quadriceps.
  • Keep the movement continuous and rhythmic to turn this into an effective cardiovascular and coordination challenge.

Make it harder

  • Increase the height of the step to deepen the lateral lunge and increase the workload on the quads and glutes.
  • Hold light dumbbells or wrist weights to add resistance to the arm arc, further challenging the shoulders and core stability.

Frequently asked

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

Related exercises

  • Air Punches MarchBeginner · calves, pectorals, and quadriceps
  • Barbell Power JerkAdvanced · adductors, calves, deltoids, glutes, hamstrings, and quadriceps
  • Barbell Snatch From BlocksAdvanced · adductors, calves, glutes, hamstrings, lats, quadriceps, serratus anterior, and trapezius
  • Basketball Shot JumpAdvanced · calves, glutes, and quadriceps

Train this with a plan, not guesswork

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

Download on the App Store