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  5. Cardio
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  7. Assault Run

Exercise guide

Assault Run

  • Intermediate
  • Compound
  • Timed hold
  • Cardio

The Assault Run is a high-intensity, dynamic lunge variation that mimics sprinting mechanics to build explosive lower-body power and cardiovascular endurance. It emphasizes the triple extension of the hip, knee, and ankle while engaging the core for stability.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Assault Run demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Calves
  • Glutes
  • Hamstrings
  • Quadriceps

Secondary

  • Abs
  • Hip flexors
  • Obliques

Equipment

  • Body weight

Setup

  1. Stand tall with your feet hip-width apart and your core engaged.
  2. Position your arms in a 'ready' athletic stance, bent at 90 degrees.
  3. Ensure you have a clear path ahead or enough space to alternate legs in place.
  4. Maintain a neutral spine with your gaze fixed forward.

How to do it

  1. Step forward into a deep lunge, lowering your back knee toward the ground while keeping your front shin nearly vertical.
  2. Explosively drive through the mid-foot of your front leg to propel yourself upward and forward.
  3. Switch legs in mid-air or during a quick transition step, immediately descending into a lunge on the opposite side.
  4. Inhale as you descend into the lunge and exhale forcefully as you drive upward into the next stride.
  5. Maintain a rhythmic tempo, pumping your arms in opposition to your legs (left arm forward when right leg is forward).

Form checklist

  • Keep your chest upright and avoid collapsing your torso forward.
  • Ensure your front knee stays aligned with your toes and does not cave inward.
  • Maintain a wide enough stance (tracks, not a tightrope) to preserve balance.
  • Keep your core tight to prevent excessive arching in the lower back.

Pro tips

  • Focus on driving the back knee forward and up during the transition to maximize glute and hip flexor engagement.
  • Minimize ground contact time between repetitions to increase the plyometric effect and heart rate demand.
  • Coordinate your arm swing aggressively; the faster your arms move, the faster your legs will follow.

Make it harder

  • Incorporate a vertical jump between each lunge to turn the movement into a full plyometric switch lunge.
  • Hold a pair of light dumbbells to increase the load on the quadriceps and glutes.

Frequently asked

What muscles does the assault run work?
The assault run primarily targets the calves, glutes, hamstrings, and quadriceps, and also works the abs, hip flexors, and obliques as secondary muscles.
What equipment do you need for the assault run?
The assault run requires no equipment — just your body weight.
Is the assault run good for beginners?
The assault run is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Band Assisted Sprinter RunAdvanced · calves, glutes, hamstrings, and quadriceps
  • Briskly Walking 360 DegreesBeginner · calves, glutes, hamstrings, and quadriceps
  • Butt KicksBeginner · calves, glutes, hamstrings, and quadriceps
  • High Knee To Butt KickBeginner · calves, glutes, hamstrings, and quadriceps

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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