Exercise guide
Body Extension
- Intermediate
- Isolation
- Timed hold
- Lower legs
- Upper legs
- Waist
The Body Extension is a high-tension movement that builds core stability and eccentric quadriceps strength by lengthening the body's lever arm against gravity.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Stand with your feet hip-width apart and your arms resting at your sides.
- Engage your core and tuck your pelvis slightly to maintain a neutral spine.
- Fix your gaze straight ahead to keep your neck in a neutral position.
How to do it
- Inhale and simultaneously reach your arms overhead while rising onto the balls of your feet.
- Lean your entire body forward in a straight line from your hands to your heels, extending as far as you can while maintaining balance.
- Exhale and forcefully contract your abdominals and quadriceps to pull your body back to the vertical starting position.
- Perform the movement with a controlled tempo, pausing for one second at the point of maximum extension.
Form checklist
- Maintain a 'hollow body' position by keeping the ribs tucked and the core braced.
- Ensure the movement occurs at the ankles; do not bend or 'break' at the hips.
- Keep your glutes squeezed throughout the set to protect the lower back.
- Avoid arching the lumbar spine as you reach forward.
Pro tips
- To maximize quad activation, focus on pushing through the balls of your feet as you return to the start.
- Think of your body as a solid plank; the further you lean, the more tension you create in the rectus abdominis.
Make it harder
- Increase the duration of the isometric hold at the peak of the extension to 3-5 seconds.
- Perform the movement with a slower eccentric (leaning) phase to increase time under tension.
Frequently asked
- What muscles does the body extension work?
- The body extension primarily targets the abs and quadriceps, and also works the erector spinae, glutes, and hamstrings as secondary muscles.
- What equipment do you need for the body extension?
- The body extension requires no equipment — just your body weight.
- Is the body extension good for beginners?
- The body extension is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.