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  3. Exercises
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  5. Core & Abs
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  7. Standing Side Bend Bent Arm

Exercise guide

Standing Side Bend Bent Arm

  • Beginner
  • Compound
  • Rep-based
  • Waist

The Standing Side Bend (Bent Arm) is a lateral flexion exercise that isolates the obliques to improve core stability and waistline definition. By using a bent-arm position, you increase the lever length on the core, enhancing the stretch and contraction of the lateral trunk muscles.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Standing Side Bend Bent Arm demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Stand with your feet shoulder-width apart and a slight bend in your knees.
  2. Place one hand behind your head with the elbow flared out (bent arm), and let the other arm hang straight down by your side.
  3. Engage your core and pull your shoulders back to maintain a tall, neutral spine.

How to do it

  1. Inhale and slowly lean your torso directly to the side of the hanging arm, reaching your hand toward your knee.
  2. Lower until you feel a deep stretch in the oblique of the side with the bent arm.
  3. Exhale and contract your obliques to pull your torso back to the upright starting position.
  4. Maintain a controlled 2-1-2 tempo (2 seconds down, 1 second pause, 2 seconds up).

Form checklist

  • Keep your hips and chest facing forward; do not rotate your torso or pelvis.
  • Ensure the movement is strictly lateral, as if you are moving between two panes of glass.
  • Keep the elbow of the bent arm pulled back to prevent your chest from collapsing forward.
  • Avoid shifting your weight onto one leg; keep pressure even through both feet.

Pro tips

  • Focus on the 'mind-muscle connection' by visualizing the space between your lower ribs and hip bone closing during the contraction.
  • At the top of the movement, perform a slight 'crunch' to the opposite side to fully engage the working oblique.

Make it harder

  • Place both hands behind your head to increase the resistance provided by the weight of your arms.
  • Hold a light dumbbell or kettlebell in the hanging hand to add external load to the lateral flexion.

Frequently asked

What muscles does the standing side bend bent arm work?
The standing side bend bent arm primarily targets the obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the standing side bend bent arm?
The standing side bend bent arm requires no equipment — just your body weight.
Is the standing side bend bent arm good for beginners?
Yes. The standing side bend bent arm is a beginner-friendly movement and a strong foundation to build on.

Related exercises

  • 3/4 Sit-UpBeginner · abs and obliques
  • 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
  • 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
  • 45 Degree Side BendIntermediate · obliques

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.

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