Also known as: hollow crossover crunch, crossover crunch, hollow body crunch, cross-body sit-up, hollow cross situp

What is X Crunch?

The X Crunch is a medium-level bodyweight core exercise that targets the abdominals and spinal erectors (back) while combining a hollow-body hold with a synchronized knee-and-arm crunch. It improves midline stability, endurance, and core-to-back coordination for intermediate trainees.

How to Do X Crunch

  1. Hollow body setup: Lie on your back in a hollow body position with lower back pressed to the floor, arms overhead and legs lifted, feet off the ground.
  2. Brace your core: Exhale and brace the core, drawing ribs toward pelvis; keep neck long and shoulders relaxed to avoid neck strain through the movement.
  3. Drive crunch motion: Simultaneously lift your upper body while bending knees and driving them toward your chest; move arms up and out to form an X at the peak.
  4. Hold the X position: At the top, extend arms fully to the sides and keep knees bent; pause briefly while maintaining core tension and neutral neck alignment.
  5. Return with control: Reverse the motion slowly back to the hollow hold, keeping the lower back pressed to the floor and breathing steadily between reps.

Muscle Groups

Core, Back

Description

Lie down on your back and start in a hollow body hold position with your arms elevated behind your head and legs elevated over the ground. Keep your core engaged and pressing your lower back into the ground.

Start the movement by lifting your upper body in the same movement as you bend your knees and move your arms up and then sideways.

When you knees are bent and arms are straight to your sides, you can reverse the movement until you are back into hollow body hold position.

Repeat for the required amount of times.
Movement Group: Core
Equipment: None (bodyweight only)

Progressions and Regressions

Frequently Asked Questions

What are the benefits of X Crunch?

X Crunches strengthen the rectus abdominis, obliques, and spinal erectors while improving hollow-body control and midline stability. They enhance core endurance and coordination between the abs and back for better posture and functional movement.

What common mistakes should I avoid with X Crunch?

Avoid lifting the lower back off the floor, using momentum, jerking the neck, or letting knees splay outward. Keep slow controlled reps, press the low back into the ground, and lead with the core, not the head.

How can I progress or regress the X Crunch?

Regress with a static hollow hold, bent-knee crunches, or dead-bug variations. Progress by increasing range of motion, slowing tempo, adding ankle weights or a light plate, or performing higher-rep sets for endurance.