How to do a Sit-Up
The sit-up curls the whole torso up from the floor to train the abs and hip flexors. Good form anchors the feet and rolls the spine up vertebra by vertebra, with a controlled descent. CalmArms grades range and control and counts each rep for you.
Muscles: Rectus Abdominis · Hip Flexors
Demonstration: Sit-Up
How to do it with clean form
- 1
Anchor your feet and start flat on your back, knees bent.
- 2
Roll up smoothly, curling the spine rather than jerking up.
- 3
Come up to a tall seated position without yanking the neck.
- 4
Lower under control — the eccentric is where the work hides.
Common sit-up mistakes CalmArms catches
Throwing the arms or head to generate momentum.
Bouncing off the floor between reps.
Only doing a partial curl on the way up.
Dropping back fast instead of controlling the descent.
How CalmArms grades the sit-up
CalmArms grades sit-up range and tempo, so a smooth, full curl earns more than a jerked partial.
Variations graded
Grade your sit-up on your next set.
Prop your phone and lift. CalmArms counts every rep and grades your form A–F, hands-free — on-device, no video uploaded.