Skip to content
Crucible Fit
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Pricing
Get Crucible
  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing
  • FAQ
  • Training Guides
Get Crucible
Crucible Fit

A daily functional fitness test for iPhone, Apple Watch and Android. Stations, reps and the Crux, sized to your readiness and your kit.

Download on the App StoreGet it on Google Play

Crucible Fit

  • The Crucible
  • The Week
  • Programs
  • Train Your Way
  • Apple Watch
  • Pricing

Explore

  • Training Guides
  • Exercise Library
  • FAQ
  • Press
  • Support

Legal

  • Terms and Conditions
  • Privacy Policy
  • Consumer Health Data Notice

CRUCIBLE FIT™ and Crux by Crucible Fit are trademarks of Crucible Fit, LLC.

© 2026 Crucible Fit, LLC. All rights reserved. Apple, the Apple logo, iPhone and Apple Watch are trademarks of Apple Inc., registered in the U.S. and other countries. App Store is a service mark of Apple Inc. Google Play and the Google Play logo are trademarks of Google LLC.

  1. Home
  2. /
  3. Exercises
  4. /
  5. Chest
  6. /
  7. Single Arm Punch And Side Knee Raise

Exercise guide

Single Arm Punch And Side Knee Raise

  • Intermediate
  • Compound
  • Reps + time
  • Chest
  • Lower legs
  • Shoulders
  • Upper arms
  • Upper legs
  • Waist

This dynamic standing movement combines a cross-body punch with a lateral knee drive to target the obliques, shoulders, and hip stabilizers. It improves coordination and functional core strength by integrating upper and lower body rotation in a single-sided flow.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Single Arm Punch And Side Knee Raise demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Deltoids
  • Obliques
  • Pectorals

Secondary

  • Biceps
  • Forearms
  • Serratus anterior
  • Triceps

Equipment

  • Body weight

Setup

  1. Stand with feet slightly wider than shoulder-width apart and knees softly bent.
  2. Bring both hands up to a 'guard' position near your chin with elbows tucked.
  3. Shift your center of gravity slightly onto your supporting leg to prepare for the lift.

How to do it

  1. Simultaneously punch one arm across your body while driving the knee on that same side up and out toward your shoulder.
  2. Exhale forcefully at the peak of the movement, crunching your ribs toward your hip to engage the obliques.
  3. Inhale as you return your foot to the floor and your hand to the guard position with controlled tempo.
  4. Complete the designated repetitions on one side before switching to the other.

Form checklist

  • Keep the supporting knee slightly bent to maintain balance and protect the joint.
  • Drive the knee out to the side (laterally) rather than straight forward to maximize oblique activation.
  • Maintain an upright torso and avoid rounding your lower back during the crunch.
  • Pivot slightly on the ball of your standing foot to allow for smooth hip rotation.

Pro tips

  • Focus on the 'mind-muscle connection' by imagining you are squeezing your side-waist as the knee and elbow approach each other.
  • Keep the non-punching hand glued to your face to maintain balance and simulate proper boxing mechanics.

Make it harder

  • Add a small hop on the supporting leg as you drive the knee up to transform the move into a plyometric exercise.
  • Hold a light dumbbell (2-5 lbs) in the punching hand to increase the resistance on the deltoids and core.

Frequently asked

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

Related exercises

  • Knee Tap Sky ReachIntermediate · abs, calves, deltoids, obliques, and pectorals
  • Step Side Sky PunchIntermediate · abs, calves, deltoids, glutes, obliques, pectorals, and quadriceps
  • Alternate Front Kick In Place With Arm CirclesBeginner · abs, calves, deltoids, and pectorals
  • Baseball HitAdvanced · biceps, deltoids, glutes, hamstrings, lats, obliques, pectorals, quadriceps, and triceps

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

Download on the App StoreGet it on Google Play

See how a Crucible works