Weighted Decline Crunch

Also known as: Decline Weighted Crunch, Decline Crunch with Plate, Weighted Decline Bench Crunch

StrengthCore

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Body Part: Abs

Description

Lie head-down on a decline ab bench with a weight plate on your chest and curl your trunk up off the pad to load your abs over a long range. The rectus abdominis, your six-pack muscle, does the work along its whole length, and the obliques at the sides of your waist help. Because your head starts below your hips, your abs lift the plate out of a stretch, while the floor version with a plate starts from flat. It stays a crunch, not a sit-up: your lower back never leaves the pad. Move to it once 20 clean decline crunches without a plate feel easy.

How to Perform

Set the ab bench to a moderate decline, about 20–30°. On most benches that's a middle hole, and steeper is harder.
Sit on the short top pad, hook the front of your ankles under the foot roller and bend your knees about 90° over the edge.
While you're still sitting up, press the plate flat against your upper chest and cross your forearms over it, hands reaching toward the opposite shoulders.
Lie back slowly until your shoulder blades touch the pad. Your head is now below your hips; keep it in line, chin slightly tucked.
Breathe out and pull your ribs toward your pelvis, peeling your head, then your shoulders, then your upper back off the pad.
Stop about 45° from the bench, with your shoulder blades and mid-back up and your lower back still on the pad. Squeeze for a second.
Take 2–3 seconds to uncurl until your shoulder blades touch down, and start the next rep before your head comes to rest.
Finish by sitting up first, then set the plate down beside the bench. Light-headed? Give it a few seconds before you stand.

What Muscles Work

Primary Muscle:

Tips

Take 2–4 sets of 10–20 reps close to failure. Pick a range such as 10–15 and add reps with the same plate and bench angle until you get 15 in every set with a 1-second squeeze and a slow way down. Then take the next plate up and go back to 10. Jumps from 2.5 to 5 kg or 5 to 10 kg are big for abs, so if the next plate is too much, set the bench one hole steeper with your current plate first.
The work runs down the front of your stomach, from just below the breastbone to below the navel, hardest in the squeeze at the top and the stretch at the bottom, plus some work at the sides of your waist. A burn at the front of your hips means you're sitting up too far or pulling with your legs. Stop the set if you get sharp low-back pain or pain that travels down a leg.
Substitutes: Decline Crunch (the same bench without a plate, good for learning the range), Weighted Ab Crunches (plate on the floor, a little easier), Kneeling Cable Abs Crunches and Machine Abdominal Crunches (heavier loads in smaller steps, once plates above about 20 kg get awkward to hold on your chest).

Common Mistakes

Sitting up all the way to your thighs. Once your lower back leaves the pad, the rep turns into a sit-up and you feel it at the front of your hips. Stop at about 45°, shoulder blades and mid-back up.
Pulling yourself up with your legs, shins driving into the roller. The roller only holds you in place. Think ribs to pelvis, and if you can't curl without yanking on it, use a lighter plate or a flatter bench.
Pushing the plate forward or up to swing your trunk off the pad. Keep it pinned flat to your upper chest under crossed forearms, elbows low; your arms don't move.
Dropping back and bouncing your shoulders or head off the pad. Lower in 2–3 seconds, touch down lightly with your shoulder blades and curl again from a standstill.
Leading with your head: chin jammed into the plate or neck craning forward while your trunk stays flat. Leave about a fist of space between chin and plate and let your head follow your ribcage.
Setting the bench too steep for the plate. The bottom gets away from you and your lower back arches off the pad on the way down; go a hole flatter or use a lighter plate until you can lower slowly with your back down.