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  3. Exercises
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  5. Shoulders
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  7. One Arm Front Plank

Exercise guide

One Arm Front Plank

  • Intermediate
  • Isolation
  • Timed hold
  • Shoulders
  • Upper arms
  • Waist

This advanced plank variation challenges core stability and anti-rotational strength by removing one point of contact, forcing the obliques and serratus anterior to work harder to keep the torso level. It builds exceptional functional strength in the midsection while significantly improving shoulder stability.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the One Arm Front Plank demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Deltoids
  • Obliques

Secondary

  • Erector spinae
  • Serratus anterior
  • Trapezius

Equipment

  • Body weight

Setup

  1. Start in a high plank position with your hands directly under your shoulders and feet slightly wider than hip-width for better balance.
  2. Engage your glutes and pull your belly button toward your spine to create a rigid, straight line from head to heels.
  3. Shift your weight slightly onto your supporting hand, ensuring your shoulder is stacked directly over your wrist.

How to do it

  1. Slowly lift one arm off the floor and place the hand behind your lower back or extend it straight ahead.
  2. Maintain a steady, rhythmic breathing pattern, exhaling deeply to increase intra-abdominal pressure and core engagement.
  3. Hold the position for the prescribed duration, focusing on keeping your hips and shoulders perfectly parallel to the floor.
  4. Lower the arm back to the starting position with control and repeat on the opposite side.

Form checklist

  • Keep your hips square to the floor; do not let the side of the lifted arm rotate upward.
  • Avoid shrugging the supporting shoulder toward your ear; keep the neck long.
  • Keep your neck neutral by looking at a spot on the floor about 6 inches in front of your hands.
  • Ensure your lower back does not sag or arch excessively throughout the hold.

Pro tips

  • Imagine a glass of water resting on your lower back; your goal is to keep it from spilling by resisting any rotation.
  • Actively push the floor away with your supporting hand to engage the serratus anterior and stabilize the shoulder blade.

Make it harder

  • Narrow your foot stance to decrease your base of support and significantly increase the stability demand.
  • Lift the opposite leg simultaneously (e.g., right arm and left leg) to perform a Bird-Dog Plank.

Frequently asked

What muscles does the one arm front plank work?
The one arm front plank primarily targets the abs, deltoids, and obliques, and also works the erector spinae, serratus anterior, and trapezius as secondary muscles.
What equipment do you need for the one arm front plank?
The one arm front plank requires no equipment — just your body weight.
Is the one arm front plank good for beginners?
The one arm front 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 Knee Raise Side ReachBeginner · abs, deltoids, and obliques
  • Band Half Kneeling ChopIntermediate · abs, deltoids, and obliques
  • Battling Ropes Half KneelingIntermediate · abs, biceps, deltoids, obliques, and pectorals

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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