Sit-Up Core Control
sit-up core workout
3 rounds for quality
8-12 controlled Sit-Up reps
8 controlled GHD Sit Up reps
Rest 45 sec without losing position
Bodyweight
Sit-Up — CrossFit Technique Guide
BB
By Borja Bes — CrossFit Athlete & Hyrox Finisher
The CrossFit sit-up differs from the traditional gym sit-up: it is typically performed with an AbMat (a small wedge supporting the lower back), feet butterflied out (soles together), and arms swinging overhead at the bottom and reaching forward at the top. This full range of motion engages the abs through their complete length and uses the hip flexors to generate momentum for high-rep efficiency. Sit-ups feature prominently in benchmark workouts like Annie (150 total) and across many Hero WODs as an accessory movement.
Quick answer
The CrossFit sit-up differs from the traditional gym sit-up: it is typically performed with an AbMat (a small wedge supporting the lower back), feet butterflied out (soles together), and arms swinging overhead at the bottom and reaching forward at the top. Use Sit-Up for controlled trunk work and end the set before the lower back or pelvis loses its intended position.
Curated demonstration
Watch Sit-Up Technique
Press play to watch the movement here without leaving the guide.
The AbMat Sit-up
CrossFit · reviewed 2026-08-06
Muscles Worked
Rectus abdominisHip flexorsObliques
Equipment
None (AbMat optional)
Best For, Avoid If, and Scaling
| Best for | Sit-Up trunk-control work for rectus abdominis and hip flexors that supports lifting, gymnastics and posture without relying on fast, loose repetitions. |
|---|---|
| Avoid if | Avoid or scale Sit-Up if pain changes the movement or the intended position cannot be controlled. Correct this common fault before adding volume: not reaching full lay-back at the bottom — reduces range of motion. |
| Scaling | Crunches, feet-anchored sit-ups, or reduced range of motion. |
How to Do the Sit-Up
1
Sit with feet butterflied (soles together), knees out, AbMat under lower back if available.
2
Lay back until shoulders touch the floor, arms reaching overhead.
3
Use the arm swing to initiate the movement — swing arms forward as you sit up.
4
Reach hands forward past the knees at the top — full sit-up position.
5
Control the descent back, letting arms swing overhead.
Common Mistakes
✕
Not reaching full lay-back at the bottom — reduces range of motion.
✕
Pulling on the neck — arms should swing, not pull the head forward.
✕
Anchoring feet (e.g. under a rig) in workouts where it is not prescribed — changes the movement stimulus.
Coaching Tips
✓
For fast cycling in WODs, develop a smooth arm-swing rhythm — it drives the movement and reduces muscular effort.
✓
If you lack an AbMat, a folded towel or thin cushion under the lower back works similarly.
Scaling Options
Easier / Beginner
Crunches, feet-anchored sit-ups, or reduced range of motion.
Harder / Advanced
GHD sit-ups (on a glute-ham developer — significantly harder and requires gradual introduction).
Training Examples
Train Sit-Up with a Clear Purpose
Create a similar workout
Sit-Up Trunk Finisher
sit-up finisher
Every 90 sec x 5 rounds
8-12 controlled Sit-Up reps
20 sec easy breathing reset
Stop before the lower back compensates
Frequently Asked Questions
Why does CrossFit use an AbMat for sit-ups?
The AbMat supports the lumbar spine at the bottom of the movement, allowing the abdominals to work through their full range of motion (from full extension to full flexion). Without support, the lower back lifts off the floor prematurely, shortening the range.
Build It Into a Workout
Generate a WOD with Sit-Up
Use the generator to turn this movement into a full session based on your level, equipment, and training goal. This is the fastest way to move from movement knowledge to real training.
Useful next steps
Hero WODs with Sit-Up
Related Exercises
Ready to put the Sit-Up to work?
Generate a WOD that includes this movement, calibrated to your level and equipment.