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  7. Predator Jack

Exercise guide

Predator Jack

  • Intermediate
  • Compound
  • Rep-based
  • Chest
  • Lower legs
  • Shoulders
  • Upper legs
  • Waist

The Predator Jack is a dynamic, full-body movement that combines a jumping jack with a deep squat to build explosive power and cardiovascular endurance. It targets the lower body while using a wide arm fly motion to engage the chest, shoulders, and upper back.

Reviewed by the Crucible team · Updated June 2026

Watch the Predator Jack demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Calves
  • Glutes
  • Quadriceps

Secondary

  • Abs
  • Obliques
  • Serratus anterior

Equipment

  • Body weight

Setup

  1. Stand tall with your feet together and your arms extended straight in front of your chest, palms touching.
  2. Engage your core and maintain a neutral spine with your gaze forward.
  3. Keep a slight bend in your knees to prepare for the explosive movement.

How to do it

  1. Jump your feet out wide into a sumo squat stance while simultaneously pulling your arms out to the sides in a fly motion.
  2. Inhale as you lower your hips until your thighs are parallel to the floor, keeping your chest upright and arms pulled back to squeeze your shoulder blades.
  3. Exhale and explosively jump back to the starting position, bringing your feet together and your palms back to touch in front of you.
  4. Maintain a fast, rhythmic tempo, ensuring you land softly on the balls of your feet each time.

Form checklist

  • Keep your weight in your heels during the squat phase to maximize glute activation.
  • Ensure your knees track in line with your toes and do not cave inward.
  • Maintain an upright torso; avoid rounding your lower back or leaning too far forward.
  • Land softly with knees slightly bent to absorb the impact.

Pro tips

  • Focus on the 'pull' of the arms to maximize rear deltoid and rhomboid engagement, effectively opening the chest.
  • Try to minimize the time your feet spend on the ground to increase the plyometric intensity and heart rate.

Make it harder

  • Hold light dumbbells in each hand to increase the resistance on the shoulders and chest.
  • Increase the depth of the squat and the speed of the jumps to turn it into a high-intensity interval move.

Frequently asked

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

Related exercises

  • Barbell Snatch From BlocksAdvanced · adductors, calves, glutes, hamstrings, lats, quadriceps, serratus anterior, and trapezius
  • Box Jump Through The ArmsIntermediate · calves, glutes, and quadriceps
  • Burpee Jump BoxAdvanced · calves, glutes, hamstrings, and quadriceps
  • Burpee Over The DumbbellIntermediate · calves, glutes, hamstrings, and quadriceps

Train this with a plan, not guesswork

Crucible builds the predator jack into a precise program around your body, equipment, location, and time.

Download on the App Store