Crunch

When starting out, prioritize control over speed or range of motion. You should feel a focused burn directly in your abdominal wall, not a sharp pull in your neck or lower back. True failure arrives when you can no longer maintain a neutral cervical spine or when your hip flexors begin to yank your torso upward. Stop the set immediately if you experience spinal discomfort or lose the ability to exhale fully during the curl. Common compensations include jerking the head forward with your hands, lifting the entire back off the floor, or holding your breath. Keep your chin slightly tucked, imagine a small orange resting under your chin, and move only through your thoracic spine. Mastering this isolated flexion builds a resilient midline that translates to every other movement you train. Trust the slow tempo, and let the muscles do the work.

To make this movement genuinely challenging, extend the lowering phase to three or four seconds and hold the peak contraction for a full two-count exhale. Sets of 15–20 build endurance, while sets of 8–12 with added load favour strength. Because this is bodyweight work, making it harder means increasing leverage demands rather than chasing endless repetitions. Hold a light medicine ball across your chest, or progress to holding it overhead with arms extended to lengthen the lever. Elevating your feet onto a bench removes lower-body assistance and forces deeper abdominal recruitment. Once you can complete three controlled sets of 15 with a medicine ball held overhead without your lower back leaving the floor, move on to the reverse crunch or a cable crunch, which allow more systematic loading. A slow bicycle crunch is worth knowing too, as it introduces rotation while maintaining the same deliberate spinal flexion pattern.

Most lifters sabotage the crunch by yanking their head and neck forward, which shifts tension away from the abs and strains the cervical spine. Another frequent error involves overextending the range of motion by lifting the entire lower back off the floor, turning a targeted flexion exercise into a hip-dominant movement. Rushing through reps with momentum also robs the muscle of time under tension, while holding your breath spikes intra-abdominal pressure and disrupts core engagement. Finally, planting the hands too high on the head creates a lever that encourages elbow pulling instead of abdominal contraction. Keep the movement small, deliberate, and strictly controlled to maximize effectiveness and protect your spine.

Sets

3

Reps

8-12

Rest

90s

Tempo

2-0-2-0

RPE

7

Per set

~90s

頻率

2-3x/week