Decline Crunch

The Decline Crunch is a core strengthening exercise performed on a decline bench to increase gravitational resistance and range of motion. It primarily isolates the upper rectus abdominis while engaging the deep core stabilizers more intensely than a standard floor crunch.

Exercise movement reviewed by:Cody Lockling, MS, CSCS
How Iridium Helps

Because the decline angle significantly increases spinal compression, our AI analyzes your RPE and rep performance to determine if the angle is too steep or if you are ready for added resistance. If you report lower back pain, the app immediately flags this movement and suggests safer alternatives like stability ball crunches to protect your lumbar spine. By tracking your recovery status, the AI ensures you don't overtrain your abdominals, optimizing volume based on your specific fatigue levels.

Form Cues

Do
  • Secure your feet firmly under the pads to prevent sliding
  • Contract your abs deeply to curl your shoulders off the bench
  • Exhale forcefully as you crunch up towards your knees
  • Lower your torso slowly and with control to resist gravity
  • Keep your chin tucked slightly to protect your neck
Don't
  • Don't pull on your neck or head with your hands
  • Don't use momentum or swing your body to get up
  • Don't lift your lower back off the bench
  • Don't let your head slam back onto the bench between reps
  • Don't perform a full sit-up; stop when the abs are fully contracted

Common Mistakes

  • Pulling on the neck
  • Using momentum to swing up
  • Lifting the lower back
  • Holding breath during exertion
  • Excessive range of motion

Muscles Worked

This exercise isolates the rectus abdominis, specifically emphasizing the upper region due to the spinal flexion movement pattern. By positioning your body on a decline, gravity provides constant tension throughout the rep, forcing your core to work harder than it would on a flat surface to stabilize the spine and control the descent.

Primary

Upper Abs

Secondary

General Core

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