Machine Ab Crunch
Auto DetectedA seated isolation movement using a machine to provide constant resistance for training the rectus abdominis, promoting core hypertrophy and strength.
About Exercise
Equipment
AB Crunch Machine
Difficulty
1/5 • Beginner
Primary Muscle Groups
Abs
Secondary Muscles
Obliques
Popularity Score
8
Goals
Training Style
Setup Requirements
Requires Rack
No
Requires Bench
No
Requires Spotter
No
Space Needed
Small
Noise Level
Low
Muscle Breakdown
View Muscle MapAbs
10/10Rectus Abdominis
Obliques
4/10Programming
Typical Rep Range
10-15 reps
Rest Between Sets
45-90 seconds • Use shorter rest for endurance focus.
How to Perform
Sit in the machine with your back pressed against the pad and your feet firmly on the floor or footrests. Adjust the seat and position the handles or pads against your chest or shoulders.
- Engage your core and initiate the movement by flexing your spine, crunching your chest toward your hips.
- Pull the resistance down, focusing on contracting the abdominal muscles fully at the peak crunch.
- Pause briefly, ensuring maximum core squeeze.
- Slowly control the weight as you extend your spine back up to the starting position.
- Maintain core tension throughout the entire range of motion.
Coaching Tips
Form Cues
- Squeeze the stomach
- Flex the spine forward
- Control the return
- Exhale completely
Breathing
Exhale forcefully as you crunch down (concentric phase); inhale slowly as you return to the starting position (eccentric phase).
Tempo
2-0-1
Range of Motion
Crunch until your torso is fully flexed and the abdominals are maximally contracted, controlling the return without hyperextending the back.
Safety
Safety Notes
- Do not select a weight that causes excessive strain in the lower back or neck.
- Avoid hyperextending the spine upon return.
- Ensure the machine is adjusted correctly for your body height.
Spotting
Not required; the machine stabilizes the weight and movement path.
Common Mistakes
- Using momentum or swinging the body.
- Pulling excessively with the arms or neck.
- Rushing the eccentric phase.
- Allowing the weight stack to slam.
When to Avoid
- Acute low back pain
- Spinal disk issues
- Recent abdominal surgery
Flexibility Needed
- Adequate lumbar spine flexion
Build Up First
- Ability to isolate abdominal contraction
Also known as
Machine Crunch, Seated Crunch Machine, Abdominal Crunch Machine, Ab Machine
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