Exercise guide
Fast Sit Up Slow Down
- Beginner
- Compound
- Rep-based
- Waist
This variation targets the rectus abdominis and obliques by combining explosive power on the ascent with controlled eccentric tension on the descent to maximize muscle fiber recruitment.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie on your back with your knees bent and feet flat on the floor, hip-width apart.
- Place your hands lightly behind your ears or cross them over your chest.
- Engage your core by drawing your navel toward your spine and pressing your lower back into the mat.
How to do it
- Exhale and sit up as fast as possible, bringing your torso to a full upright position.
- Inhale and begin a very slow, controlled descent back to the floor, taking at least 3 to 5 seconds.
- Lower yourself one vertebra at a time until your shoulder blades touch the mat, then immediately repeat.
Form checklist
- Keep your feet firmly planted on the ground throughout the entire movement.
- Avoid using momentum or swinging your arms to assist the upward phase.
- Maintain a slight 'C-curve' in your spine during the descent to ensure abdominal engagement.
- Keep your chin tucked slightly to avoid straining your neck.
Pro tips
- Imagine your spine is a piece of tape being slowly pressed down onto the floor one inch at a time during the lowering phase.
- Focus on the mind-muscle connection by squeezing your abs hard at the top of the movement before starting the slow descent.
Make it harder
- Extend your arms straight overhead to increase the lever length and resistance.
- Hold a small weight plate or medicine ball against your chest.
Frequently asked
- What muscles does the fast sit up slow down work?
- The fast sit up slow down primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
- What equipment do you need for the fast sit up slow down?
- The fast sit up slow down requires no equipment — just your body weight.
- Is the fast sit up slow down good for beginners?
- Yes. The fast sit up slow down is a beginner-friendly movement and a strong foundation to build on.