Muscles worked
What the sit-up trains
Tap a muscle to see just that one and what it does in the lift.
Before the first rep
How to set up
- 01
Lie down. Lie on your back on a mat with your knees bent to about 90 degrees and your feet flat on the floor, about hip width apart.
- 02
Anchor if needed. If your feet lift as you rise, tuck them under a heavy dumbbell, a low bar or a partner's hands. Try to need the anchor as little as possible.
- 03
Arms. Cross your arms over your chest, which is the standard version. Fingertips lightly at your temples is harder; reaching your arms forward is easier.
- 04
Neck and brace. Leave a fist sized gap between your chin and chest and gently tighten your abs before the first rep.
Step by step
How to do the sit-up
- 01
Breathe out and curl. Exhale and curl your head, then your shoulder blades, off the floor by pulling your ribs toward your hips, the same way a crunch starts.
- 02
Keep rolling up. Keep peeling your spine off the floor one section at a time until your lower back lifts and your torso comes up toward your thighs.
- 03
Sit tall. Finish sitting upright with your chest over your hips. Your feet stay down and your knees stay bent.
- 04
Lower slowly. Breathe in and roll back down over two or three seconds, lower back first, then your shoulder blades, keeping your abs tight the whole way.
- 05
Touch and go. Let your shoulder blades touch the floor lightly, keep your head up off the mat and start the next rep without bouncing or swinging.
Cues to say in your head
- Ribs to hips first
- Peel up one section
- Chest over hips
- Roll down slowly
- Blow out going up
- No swinging arms
Fix these first
Common mistakes
Yanking up with your arms or head
Cross your arms or keep fingertips light at your temples. If you need momentum, reach your arms forward and shorten the range instead of jerking.
Sitting up with a flat back
Start every rep with a curl from your ribs. Rising stiff from the hips turns the rep into mostly hip flexor work and can tug on your lower back.
Dropping back to the floor
Take two or three seconds to lower and roll down through your spine. The way down trains your abs as much as the way up.
Feet popping up
Anchor your feet, or bring your heels a little closer to your glutes. If they still lift, the full sit up is too hard for now; build up with crunches and partial reps.
Tucking your chin hard
Keep the fist sized gap under your chin and lead with your chest. Your neck should feel almost nothing.
Holding your breath
Breathe out as you curl up and in as you lower. Exhaling helps your ribs pull down at the start of the rep.
Stay safe
Floor sit ups are low risk for most people. Stop if you feel sharp pain in your lower back or neck rather than effort in your abs, and drop to a shorter range or crunches if your back complains. Ending a set is simple: stop the rep and roll back down. The decline and GHD versions are much harder: build up in small steps, keep a GHD to parallel until you are well practiced, and never jump into high rep GHD sets, because they can leave you extremely sore and, in rare cases, cause serious muscle breakdown. Get medical help right away if you have severe muscle pain with dark urine after a hard session. If you are pregnant or postpartum, have a hernia, or are dealing with a back injury, check with a doctor or physical therapist first.
Programming
Sets, reps and how much weight
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Muscle | 3 to 4 | 10 to 15 | 60–70% 1RM | 60 to 90 sec |
| Endurance | 2 to 3 | 15 to 25 | 40–55% 1RM | 30 to 60 sec |
| Technique | 2 to 3 | 6 to 10 | 40–50% 1RM | 45 to 60 sec |
Plan your next session
Put in a recent set. You get working weights for your goal, a warm-up and the plates to load.
Estimated 1RM 216 lb
Endurance sets
86–119lb
2 to 3 sets of 15 to 25 reps, 30 to 60 sec rest. Bodyweight only. End the set as soon as you start swinging or your feet lift.
Estimates use the Epley formula and work best from sets of 3 to 8 reps. Treat them as a starting point and adjust by how the first working set moves.
Questions
Sit-Up questions
What muscles do sit ups work?
Sit ups mainly work the rectus abdominis, the six pack muscle, with help from the obliques. In the top half your hip flexors, the muscles at the front of your hips, do much of the lifting to bring you upright.
How do you do a decline sit up?
Set a decline bench at its lowest angle, hook your feet under the pads and sit with your knees bent. Roll down under control until your shoulder blades are just above the pad, then curl up until you are sitting tall, lowering slowly each rep.
How do you do a GHD sit up?
Sit on a glute ham developer with your glutes on the pad and your feet hooked under the rollers, knees slightly bent. Lower your torso under control to about parallel with the floor, then drive up by straightening your knees against the rollers, letting your hip flexors pull you upright until your chest is over your hips. It is an advanced move: start with one or two sets of a few reps and build up over several weeks.
Should I anchor my feet for sit ups?
Anchor them if your feet lift and you cannot complete reps otherwise. Anchored feet let your hip flexors pull harder, so as you get stronger, try doing some reps with your feet free.
Are sit ups bad for your back?
Not for most healthy people when done slowly with a curled spine. If they cause lower back pain, shorten the range, stop anchoring your feet, or switch to exercises like the dead bug and plank, and get pain that keeps coming back checked.
How many sit ups should I do?
Two or three sessions a week of 3 sets of 10 to 15 slow reps is plenty for most people. Make them harder with a light plate or a decline bench rather than doing hundreds of fast reps.
Train in Protocol
Log your sit-up by voice. Protocol tracks the rest.
Your last session shows up before every set, warm-ups and plates are worked out for you, and your coach sees every lift next to your sleep and recovery.