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Core: flexion

Sit-up

Quick facts

  • Beginner
  • No equipment
  • Core
  • Hip flexors
  • reps
  • ~2.5 s per rep
Do workout 1 for free See the course

The sit-up is the classic dynamic abs exercise: from lying on your back you rise to a seated position and return. Unlike a short crunch it works the rectus abdominis and the hip flexors through a full range, which is why sit-ups are a staple of CrossFit workouts. Do them smoothly and without jerking so the spine stays safe and the abs get all the work.

How to do it

  1. Lie on your back with knees bent, feet flat and hip-width apart, arms crossed on your chest or reaching forward.

  2. Tuck your chin slightly, brace your abs and start peeling your head, shoulders and shoulder blades off the floor, curling up one vertebra at a time.

  3. Rise all the way to sitting, chest toward your knees, feet staying on the floor.

  4. Lower back down along the same path until your shoulder blades touch the floor, then begin the next rep.

Coaching cues

  • Curl up, don't rise like a board
  • Chin tucked
  • Feet stay down

Common mistakes

  • Yanking with the arms and neck instead of using the abs
  • Dropping back down without control
  • Feet lifting off and the legs kicking up

Breathing

Exhale as you rise, inhale on the way down.

Easier and harder versions

Used in courses

Related exercises

FAQ

What are the most common mistakes in Sit-up?

The most common ones: yanking with the arms and neck instead of using the abs; dropping back down without control; feet lifting off and the legs kicking up. Watch for them from the first rep.

What should I focus on during Sit-up?

Keep these cues in mind: curl up, don't rise like a board; chin tucked; feet stay down.

How should I breathe during Sit-up?

Exhale as you rise, inhale on the way down.

Train it inside a program

Sit-up is part of the Forma. Start: home CrossFit basics course: the app scales reps, rest and load to your level after every session.

Do workout 1 for free See the course