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  7. 5 Sec Fist Against Chin

Exercise guide

5 Sec Fist Against Chin

  • Intermediate
  • Isolation
  • Rep-based
  • Back
  • Chest
  • Shoulders
  • Upper arms
  • Waist

This isometric exercise targets the anterior neck flexors to improve cervical stability and posture by resisting downward force without movement.

Reviewed by the Crucible team · Updated June 2026

Watch the 5 Sec Fist Against Chin demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Neck

Secondary

  • Biceps
  • Deltoids
  • Forearms
  • Grip muscles
  • Trapezius

Equipment

  • Body weight

Setup

  1. Sit or stand tall with your shoulders back and down.
  2. Place one fist directly under your chin, centered against the jawline.
  3. Ensure your head is in a neutral position, looking straight ahead.

How to do it

  1. Exhale and gently press your chin down into your fist while resisting with equal force from your hand to prevent any movement.
  2. Maintain this isometric contraction for 5 seconds while keeping your breathing steady and shallow.
  3. Inhale as you slowly release the tension and return to a relaxed neutral position.

Form checklist

  • Keep your shoulders relaxed; do not shrug them toward your ears.
  • Ensure the head remains stationary throughout the hold.
  • Keep your jaw relaxed and teeth slightly apart to avoid clenching.
  • Apply pressure gradually to avoid sudden strain on the neck.

Pro tips

  • Focus on a slight 'chin tuck' before applying pressure to engage the deep cervical flexors rather than just the superficial muscles.
  • Visualize lengthening the back of your neck toward the ceiling during the contraction to maintain spinal alignment.

Make it harder

  • Increase the hold duration to 10-15 seconds per repetition.
  • Apply maximum manual resistance with your fist while maintaining perfect head alignment.

Frequently asked

What muscles does the 5 sec fist against chin work?
The 5 sec fist against chin primarily targets the neck, and also works the biceps, deltoids, forearms, grip muscles, and trapezius as secondary muscles.
What equipment do you need for the 5 sec fist against chin?
The 5 sec fist against chin requires no equipment — just your body weight.
Is the 5 sec fist against chin good for beginners?
The 5 sec fist against chin is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

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  • Battling Ropes Jumping JackIntermediate · calves, glutes, and quadriceps
  • Behind The Head Ball SlamIntermediate · abs, calves, lats, obliques, and pectorals

Train this with a plan, not guesswork

Crucible builds the 5 sec fist against chin into a precise program around your body, equipment, location, and time.

Download on the App Store