Pain guide · Back pain

Lower back pain when doing sit-ups: the arch, the hip flexors, the tailbone, crunches and what helps

Lower back pain when you do sit-ups usually starts once your shoulder blades are off the floor, when the hip flexors take over and pull your lower back up: in a lab model, full sit-ups loaded the lower spine with more than 3,000 newtons whether the knees were bent or straight. Holding your feet down hands even more of the work to the hip flexors, and a hard floor presses on the tailbone and the bony bumps of the spine. A crunch or curl-up with your feet free, a mat under your tailbone and fewer reps usually ease it. Sit-ups aren't proven to harm healthy backs: in young soldiers, sit-up training caused no more injuries or back pain than core exercises. With thin bones, though, UK guidance says swap them.

This guide starts with the signs that need help, from a 999 call for numbness around your genitals or bottom, new bladder or bowel trouble or weakness in both legs, to the hernia warning signs and a same-day check through the National Health Service's 111 line (NHS 111) or a general practitioner (GP) for back pain with a fever or after an injury. It then maps the causes by where it hurts (the back, the tailbone, the hip flexors, the tummy wall, a nerve), explains what the lab studies and soldier trials show, and don't, about anchored feet, bent knees and decline and glute-ham developer (GHD) sit-ups, shows how to change your sit-ups today, and gives a three-stage plan with a 3D demo of every move, from heel taps back to full sit-ups.

3-stage exercise plan When to get help 54 sourcesUpdated 28 October 2026

When to get help first

Exercise is for pain that has been checked or is clearly mild and settling.

Get urgent medical help if

Call 999 or go to A&E: loss of feeling or numbness around the genitals or bottom, new trouble peeing or controlling your bladder or bowels, changes in genital sensation during sex or problems with erections or orgasm, or pain, tingling, weakness or numbness in both legs. These are signs of cauda equina syndrome, which needs treating in hospital urgently. Don't drive yourself.
Call 999 or go to A&E: back pain with chest pain, or back pain that started after a serious accident, such as a car crash.
Same day (GP or NHS 111): back pain and you feel hot, cold, shivery or generally unwell, or severe pain that starts suddenly or is getting worse quickly.
Same day (NHS 111): back pain after a new, significant injury in the last 7 days, such as a fall from a height (off a box, a bar or rings) or a direct blow to the back.
Call 999 or go to A&E now if you have a femoral hernia (a small lump at the top of your thigh, in your groin) and very bad tummy pain, you feel sick or you're being sick, you cannot fart or poo, you have a high temperature or you feel hot, cold or shivery, or you've suddenly become confused. Do not drive to A&E. With any other hernia and pain in or around it, a bloated tummy, feeling or being sick, vomiting blood or vomit that looks like coffee grounds, constipation, a high temperature or feeling hot, cold or shivery, or sudden confusion, get help from NHS 111.
Call 999 or go to A&E: tummy pain that started suddenly and is severe, you're vomiting blood or your vomit looks green or like ground coffee, there's a lot of blood coming from your bottom or your poo is black and sticky, you cannot pee at all, you cannot poo or fart at all, you have spots or a rash that does not fade when you press it (it may be harder to see on brown or black skin), or you're struggling to breathe. Don't drive yourself.
If you take a blood thinner (an anticoagulant) and notice severe bruising or bleeding, get medical help immediately: call 111 or go to A&E. A painful lump in the tummy wall that grows after a cough, a strain or a knock can be bleeding into the muscle (a rectus sheath haematoma), which is more likely on blood thinners and easily mistaken for a strain.
Call 999: sudden, severe pain in the tummy or back, which can come with breathlessness, pale or grey skin, or collapse. It can be a burst abdominal aortic aneurysm, most common in men aged 65 or over and in people who smoke or used to smoke.
Same day: leg weakness that is getting worse.
Same day (urgent GP appointment or NHS 111): new difficulty lifting the front of your foot or toes (foot drop), or a foot that slaps down or catches as you walk, especially if it is getting worse. Weakness in both legs, or with numbness around the genitals or bottom or bladder or bowel changes, is the 999 emergency above.
Same day (call NHS 111, or go to A&E if you feel very unwell): after a big or unusual session, such as hundreds of squats, sit-ups, back extensions or burpees, a challenge or a new class, muscle pain, swelling or weakness far worse than the session explains, and dark pee (red, brown, tea or cola coloured), sometimes starting hours or days later. Dark pee isn't always there, so muscles far sorer, more swollen or weaker than the session explains still need the same-day check. It can be rhabdomyolysis, a breakdown of muscle that can harm the kidneys.
Call 999: sudden, severe pain in a swollen, tight muscle.
Same day: you have or have had cancer, and new back pain that is severe and doesn't let up, is getting steadily worse, is worse at night and disturbs your sleep, is worse when you cough, sneeze or strain, or comes with tenderness over the spine. Contact your cancer team or GP urgently. With cancer, new weakness, difficulty walking, numbness or bladder or bowel problems are an emergency.
A painful lump at the top of your bottom, between the buttocks, that is bleeding or leaking pus: ask for an urgent GP appointment or contact NHS 111. It can be an infected pilonidal sinus.

See a doctor or physiotherapist if

Back pain that hasn't improved after a few weeks of looking after it at home, stops you doing day-to-day activities, worries you, or you're struggling to cope.
Pain that doesn't improve with rest or is worse at night, or pain that is worse when you sneeze, cough or poo.
Unexplained weight loss, or a lump, swelling or change in the shape of your back.
Pain, tingling or numbness spreading below the knee that isn't settling after a few weeks, is getting worse or stops your normal activities: see a GP.
A lump in the groin, upper thigh or tummy, especially one that appears when you cough or strain and goes when you lie down: see a GP, as it may be a true hernia. A femoral hernia (a small lump at the top of the thigh, mainly in women over 50, though it can happen to anyone) needs treating in hospital.
A ridge or doming down the middle of your tummy when you strain, during or after pregnancy: see our diastasis recti guide, and ask about a pelvic health physiotherapist.
A strain that is getting worse, or isn't feeling better after looking after it yourself: see a GP or physiotherapist. In many areas you can refer yourself to physiotherapy.
A teenager or young adult whose low back pain is worse arching backwards and hasn't settled after a couple of weeks: stop the lifts that arch the back and get it checked by a GP or a sports medicine doctor or physiotherapist. It can be a stress fracture of the spine (spondylolysis), which usually does well without surgery when it's found.
Sudden new back pain after a minor fall, lift, cough or sneeze, from 50 or past the menopause, or if you take long-term steroid tablets; or height loss, a curved spine or a change in posture: see a GP. It can be a spinal fracture.
Back pain that started before 45 and has lasted more than 3 months, especially if it started before 35, wakes you in the second half of the night, comes with buttock pain, gets better with movement or within 48 hours of anti-inflammatory painkillers, or you have or have had arthritis, pain where a tendon attaches to bone (enthesitis) or psoriasis, or a parent, brother, sister or child with spondyloarthritis. These can point to inflammatory back pain (axial spondyloarthritis, such as ankylosing spondylitis). The National Institute for Health and Care Excellence (NICE) asks GPs to refer people with 4 or more of these 9 features to a rheumatologist, and to do a blood test for the HLA-B27 gene marker if exactly 3 are present, referring if it is positive.
Tailbone pain that hasn't improved after a few weeks of treating it at home, is affecting your daily activities, or comes with a high temperature and pain somewhere else, such as your tummy or lower back: see a GP. In many areas you can refer yourself to NHS physiotherapy.

Where does it hurt?

Location narrows the likely causes; it does not diagnose.

Across the lower back, one or both sides, as you sit up past your shoulder blades or as you lower, worst with full, decline or weighted sit-ups

Usually ordinary low back pain brought on by bending under load, the commonest kind. A crunch or curl-up, a smaller range and fewer reps usually ease it.

Read: Back pain →A sudden catch or sharp pain on one side during a rep, sometimes with the muscles locking up

Usually a pulled back muscle or a back spasm, which settles over days to weeks.

Read: Back spasm and pulled back muscle →An even ache across the lower back or tummy a day or two after a new or bigger ab session

Muscle soreness. Muscles far sorer, more swollen or weaker than the session explains, especially with dark pee, need a same-day check.

Read: Back pain after a workout →The tailbone or the bony bumps down the middle of the lower back, sore where they press the floor, sometimes with a red or rubbed patch of skin

Usually the hard floor pressing and rubbing on the bone and skin (our reading: no study has counted it). A thick mat or a folded towel usually fixes it; tailbone pain that lingers when you sit is covered by our tailbone guide.

Read: Tailbone pain →The front of the hip or groin as you sit up, worse with your feet held down

The hip flexors working hard, or a hip flexor strain.

Read: Hip flexor pain →A deep pinch in the groin as you come up

Possibly the hip joint itself.

Read: Hip pain lifting your leg →A sudden sharp pain in one spot of the tummy wall, sore to tense, twist, cough or sit up

Usually a strained tummy muscle.

Read: Abdominal strain →Low in the tummy just above the groin crease, worse with sit-ups, coughing or sneezing, with no lump

Often inguinal-related groin pain, sometimes called a sports hernia.

Read: Sports hernia →A lump or bulge in the groin, at the top of the thigh or near the belly button, bigger when you strain or cough and smaller lying down

A possible hernia: see a GP, and read the warning signs for when it is urgent.

Read: Groin pain →

A ridge or doming down the middle of the tummy as you curl up, during or after pregnancy

A gap between the six-pack muscles (diastasis recti): ease off that move for now, and ask about a pelvic health physiotherapist.

Down one leg below the knee, with tingling, numbness or weakness

Sciatica, often from a disc.

Read: Sciatica →A scan report says bulging or herniated disc

Disc changes are common in people without back pain.

Read: Herniated or bulging disc →A teenager or young athlete whose back hurts more arching backwards, building over weeks

Possibly a stress fracture of the spine (spondylolysis): get it checked, as the warning signs say.

Read: Spondylolisthesis →Sudden pain after a minor fall, lift, cough or sneeze, from 50 or past the menopause, or on long-term steroid tablets

A possible spinal fracture from thin bones: see a GP.

Read: Spinal compression fracture →The front of the neck, not the back

The neck muscles lifting your head through every rep.

Read: Neck pain in sit-ups →

A painful lump at the top of the bottom, between the buttocks, that bleeds or leaks pus

Possibly an infected pilonidal sinus, not the sit-ups: see the warning signs.

Sudden severe tummy pain spreading to the back, a fever, or pain that doesn't change when you move

Not a sit-up problem: see the warning signs.

Understand it

What a sit-up asks of the lower back, and what no study has countedEmerging evidence

A crunch curls your head and shoulders up until the shoulder blades leave the floor, bending mostly the upper back. A sit-up keeps going until your trunk is upright, so the hip flexors (the psoas, the iliacus and the rectus femoris) pull the pelvis and lower spine up too: every form of sit-up worked the psoas at 15% to 35% of its maximum in 8 adults, against under 10% in a curl-up.

That second half is where the lower back's load climbs. In a lab model of 12 young men, compression of the lower spine passed 3,000 newtons (N) in both bent-knee and straight-leg sit-ups. A curl-up that lifts only the shoulder blades bent the lower back about 3 degrees, against 38 in a full sit-up, and of 12 ab exercises tested in 9 volunteers, partial curl-ups gave the most tummy-muscle work for the least spine load.

No study has counted back pain caused by sit-ups or tested a change to the sit-up for back pain. The evidence is lab and modelling studies in healthy young adults, trials in young soldiers, trials of exercise for back pain in general, a UK consensus on osteoporosis, case reports and NHS pages. That a sore back complains at the moment the hip flexors take over is our reading of these studies.

Sources 1, 2, 3, 4, 5, 6, 7, 8

Where it hurts, and who gets itEmerging evidence

No study gives the share of each cause in sit-ups. An ache across the lower back as you curl or lower is usually ordinary low back pain, the commonest kind: the NHS names a pulled muscle (strain) as a common cause of back pain and says back pain is rarely caused by anything serious.

The people it usually bothers, in our reading: people who jump to full, decline, weighted or GHD sit-ups, timed tests or challenges after little ab work; people whose back already dislikes bending forward; and people training on a hard floor with little padding.

Some pain during sit-ups isn't the back. A sudden sharp pain in one spot of the tummy wall is usually a strain; one man's six-pack muscle was damaged after he started 30 to 40 sit-ups a day. A lump that is bigger when you strain and smaller lying down can be a hernia, which the NHS asks a GP to examine. A ridge down the middle of the tummy during or after pregnancy is a gap between the six-pack muscles: about half of first-time mothers have one at 6 weeks, and the NHS says it usually closes by 8 weeks after the birth.

Sources 9, 10, 11, 12, 13, 14, 15

The hip flexors and anchored feetEmerging evidence

Holding the feet down lets the hip flexors pull you up. With the feet fixed, tummy-muscle activity fell and rectus femoris (a hip flexor) activity rose in 14 people; in 23 British Army personnel, feet-held sit-ups and curl-ups drew more rectus femoris work, rising as they tired; and in 6 men, bent and supported legs raised hip flexor work in full sit-ups without adding tummy work. In a review of 9 studies, the iliacus worked at about 80% of its maximum in full sit-ups with the feet supported, against about 17% in a trunk-only curl.

No study has measured spine load with the feet held against free, so the honest message is about where the work goes: anchored feet mean more hip flexor work. Two muscle activity studies called the bent-knee sit-up's high hip flexor work possibly a problem for people with back problems, which is the authors' opinion, and the traditional army sit-up was mostly hip flexion.

Sources 16, 17, 18, 19, 20, 21, 22

The tailbone and the bony spineEmerging evidence

"Sit ups hurt my tailbone" is the first thing Google suggests after "sit ups hurt my". Lying on a hard floor and rolling up presses and rubs the tailbone and the bony bumps of the lower spine on every rep. The NHS lists a fall onto the coccyx and "repeated or prolonged strain on the coccyx" among causes of tailbone pain, and says it is often worse sitting, sitting down or standing up, bending forward and having a poo.

No study links sit-ups to tailbone pain or to rubbed skin over the spine, so the floor explanation is our reading. A thick mat, a folded towel under the tailbone, a smaller range and no rocking are our suggestions; tailbone pain that lingers when you sit belongs to our tailbone pain guide.

Source 11

Discs, bending and the pig spine studiesMixed evidence

Disc pressure rises with forward bending and with many commonly prescribed strengthening exercises. Young pig neck segments herniated when they were bent and straightened over and over under load, up to 86,400 times at one a second.

The review that weighs these studies points out they used dead animal tissue bent continuously, far beyond any workout, that living tissue adapts, that it is premature to say a human spine has a limited number of bends, and that no study has tested bending exercise on living human spines. In lifting, a rounded back hasn't been shown to cause back pain (low-quality evidence from 11 studies), though even physiotherapists tend to see round-back bending as dangerous. With an irritable disc or leg pain, bending forward often provokes symptoms, which is why our herniated disc guide swaps sit-ups for the dead bug and McGill curl-up while it settles.

Sources 23, 24, 1, 25, 26

Osteoporosis: the clear exceptionStrong evidence

The UK consensus on exercise for osteoporosis says movements that involve sustained, repeated or end-range bending of the spine should be modified or avoided, especially with a weight, and notes reports of spinal fractures with sit-ups. It is an expert recommendation built mainly on one small, old study that wasn't randomised: new fractures followed in 8 of 9 women given flexion exercises, against 4 of 25 given extension exercises.

The Royal Osteoporosis Society names sit-ups among exercises that "can put pressure on the spine" and teaches bending from the hips instead. The consensus also says inactivity should be avoided: the dead bug, bird dog and plank train the trunk without rounding it.

Sources 8, 27, 28

What a scan shows, and when a test mattersStrong evidence

The National Institute for Health and Care Excellence (NICE) says "Do not routinely offer imaging in a non-specialist setting" for back pain. In 3,110 people without back pain, disc wear on scans rose from 37% at 20 to 96% at 80, and disc bulges from 30% to 84%, so a report of a bulging disc doesn't explain pain on its own. An NHS emergency department leaflet says imaging "is not usually required".

A test matters for the cauda equina signs, which need an emergency magnetic resonance imaging (MRI) scan, the only way to confirm or rule it out according to an NHS spinal team's leaflet; for sudden pain after a minor fall, lift or cough with thin bones; for a teenager whose back hurts more arching backwards; and for a lump that may be a hernia, which a GP examines first.

Sources 29, 30, 31, 32, 33

How it usually goesStrong evidence

No study follows back pain from sit-ups. In new back pain, across 33 groups of people (11,166 in all), average pain fell from 52 out of 100 at the start to 23 at 6 weeks, 12 at 26 weeks and 6 at a year; in pain that had already lasted, it fell more slowly, from 51 to 23 at a year.

The NHS says back pain usually improves within a few weeks but can last longer or keep coming back, and that sciatica usually gets better in a few weeks to a few months. Herniated discs often shrink on their own. The NHS asks for a GP if tailbone pain hasn't improved after a few weeks. No one can promise a date.

Sources 34, 9, 35, 36, 11

What helps, and how strong the evidence is

Sit-ups and soldiers: no extra harm foundStrong evidence

In a trial of 1,141 soldiers over 16 weeks, replacing sit-up training with core stabilisation exercise didn't change how many were injured (44.8% overall). Soldiers who hurt their lower back lost a little more time in the sit-up group (8.3 against 4.2 days of restricted work), a difference the authors called marginal. In 2,616 soldiers, 12 weeks of core work instead of sit-ups left sit-up test scores no worse, and slightly more passed (5.6% against 3.9%). In 4,147 soldiers followed for 2 years, a daily sit-up and crunch programme led to no more back pain needing care than core stabilisation, while a short reassuring talk about back pain cut it.

These were young soldiers without back pain, so they show sit-ups aren't harmful for healthy young backs, not that they suit a sore one. The US Army's fitness test no longer includes sit-ups, but the review we found gives no injury reason for the change.

Sources 6, 37, 7, 38

Exercise helps back pain, but no type is specialStrong evidence

Across 249 trials, exercise cut long-lasting back pain by about 15 points out of 100 against no treatment, usual care or a placebo (moderate certainty), and harms were mostly minor soreness. Motor control ("core") exercise was no better than other exercise (29 trials, 2,431 people). NICE suggests a group exercise programme of any type, and a US physical therapy guideline lists trunk strengthening and endurance among the types to use but says no one type can be recommended over another.

The only trial we found that used sit-ups as treatment gave 18 people an assisted sit-up device and 18 core stabilisation work, and both groups improved. In 56 people with long-lasting back pain, a home programme of bending exercises did slightly worse for average pain at a year than extension exercises, with no difference in function or worst pain. So this plan uses back pain trials' kinds of exercise and brings sit-ups back last.

Sources 39, 40, 29, 41, 42, 43

Crunches and curl-ups: the same muscles, less loadEmerging evidence

Partial curl-ups gave the most tummy-muscle work for the least spine load of 12 exercises in 9 volunteers, a shoulder-blade curl-up bent the lower back 3 degrees against 38 in a full sit-up, and full sit-ups passed 3,000 N of modelled compression with the knees bent or straight. In 14 people, the crunch worked the six-pack as hard as most ab machines. None of these studies included people with back pain, so swapping to a crunch or curl-up while your back is sore is a sensible reading of lab data, not a tested treatment.

One expert review suggests about 60 bending reps a session at most and about 48 hours between bending sessions; that is opinion, and nobody has tested it.

Sources 5, 4, 3, 21, 1

Pregnancy, a gap between the tummy muscles, and herniasEmerging evidence

The NHS says to avoid sit-ups, planks and high-impact exercise to start with after a birth. Later, curl-ups needn't be banned: in 70 women with a gap 6 to 12 months after a birth, 12 weeks of head lifts and curl-ups neither widened the gap nor worsened back pain, and built strength; a crunch even narrows the gap while it is being done (84 and 38 women).

No study we found shows sit-ups cause hernias, and the NHS doesn't say so. After a groin hernia repair, the NHS says no heavy lifting or strenuous activity for at least 4 to 6 weeks, and after open tummy surgery one NHS trust waits 6 weeks for jogging and swimming and 12 weeks for contact sport. Follow your surgical team.

Sources 14, 44, 45, 46, 12, 47, 48

Rare harms from big sit-up sessions and strainingEmerging evidence

These are case reports, so they are rare. A man's six-pack muscle was damaged after he started 30 to 40 sit-ups a day; a teenager developed muscle breakdown with cola-coloured urine after a conditioning session including sit-ups; a woman bled into her tummy muscle after ab training; and two young men had a stroke and a bleed beside the spinal cord during sit-ups with breath-holding. The practical lessons: build sit-up volume over weeks, breathe out as you curl rather than holding your breath, and treat far more soreness than the session explains, or a painful lump in the tummy wall, as the warning signs say.

Sources 15, 49, 50, 51

How much pain is OK while you exercise?

Up to about 5 out of 10, no worse the next morning, never into a legEmerging evidence

This guide uses the back hub's rule, as our other back movement guides do. Some discomfort during exercise is fine, and it does not mean you are doing damage. Aim for pain you would call mild to moderate, no more than about 5 out of 10. It should settle within an hour or so, and your back should be no worse the next morning. If it is worse, do less next time (fewer reps, a smaller range, a lighter load), not nothing. Leg symptoms are the exception: stop or shrink any movement that sends pain, pins and needles or numbness further down a leg. The 5 out of 10 figure matches NHS inform's back exercise bands (0 to 3 minimal, 4 to 5 acceptable, 6 to 10 excessive, and no worse the morning after); an NHS trust's back leaflets allow discomfort that eases within 2 hours; the NHS back pain page is stricter, saying stop if your pain gets worse and see a GP. In long-lasting pain, exercise into some pain did no worse than pain-free exercise (7 trials, 385 people, only one in back pain).

For sit-ups (our suggestion, built on the same rule): judge each set by its last reps, and use the step of the ladder (the curl-up, the crunch, the 3/4 sit-up, the full sit-up, then decline or GHD sit-ups), the range, the floor padding and the number of reps where those reps stay at 5 out of 10 or less, settle within an hour and leave your back no worse the next morning. If not, go back one step, not to nothing.

Three things aren't pain-rule questions: pain, tingling or numbness spreading down a leg; a sharp pain in one spot of the tummy wall or a bulge there (our abdominal strain guide keeps a lower ceiling of 3 to 4 out of 10 for a recent strain); and a ridge or doming down the middle of the tummy after pregnancy.

Sources 52, 53, 54, 9

The exercise plan: 3 stages

Start at the first stage. Each move opens a full guide with a 3D demo.

Stage 1

Keep moving, and take the full sit-up out

About the first 2 weeks: daily walking, and trunk work that trains the tummy muscles without curling the lower back off the floor or pulling with the hip flexors. No full, decline or GHD sit-ups, V-ups or weighted crunches for now. With a diagnosed condition (sciatica or a disc, a tummy strain, a hernia or a repair, a gap after pregnancy, tailbone pain, a spinal fracture from thin bones), that guide's plan comes first; after surgery, the surgical team's plan does.

Treadmill walking demonstrated on the 3D figure

3D demoTreadmill walkingBeginner · Cardio machine

5 to 10 min, several times a day · As in our back pain guide (editorial); outdoors is just as good. The NHS says stay active

Harder: Treadmill jogging

Dead bug heel taps demonstrated on the 3D figure

3D demoDead bug heel tapsBeginner · No equipment

2 sets of 6 to 8 each side · As in our back pain guide (editorial). Lower each foot only as far as your back stays still

Easier: Bent-knee fall-out · Harder: Forearm plank

Knee plank demonstrated on the 3D figure

3D demoKnee plankBeginner · No equipment

3 holds of 20 to 30 s · Our beginner core workout's dose, as our neck sit-up guide uses it (editorial)

Harder: Forearm plank

3D demoBird dogBeginner · No equipment

2 to 3 sets of 6 to 8 each side, 3 to 5 s holds · As in our back pain guide (editorial)

Easier: Bird dog, one limb at a time · Harder: Bear crawl

Glute bridge demonstrated on the 3D figure

3D demoGlute bridgeBeginner · No equipment

2 to 3 sets of 10 · As in our back pain guide (editorial); an NHS trust back leaflet holds the bridge for 2 seconds, 10 times

Easier: Pelvic tilt into bridge · Harder: Single-leg glute bridge

3D demoCat-cowBeginner · No equipment

8 slow waves, small range · The move page's dose

Harder: Half lord of the fishes (Ardha Matsyendrasana)

Move on when: You can walk for 15 to 20 minutes and get through normal daily tasks, heel taps and knee planks pass the pain rule, and your back is no worse the next morning (as in our back pain guide's first stage).

Follow along: a timer, a cue and the next move, one step at a time.

Stage 2

Curl a little, with the lower back down

About weeks 2 to 6, 2 or 3 core sessions a week, plus walking: the tummy muscles working through a small curl of the upper back, the partial curl-up that gave the most tummy work for the least lower back load in the lab, and holds that resist arching and bending sideways.

McGill curl-up demonstrated on the 3D figure

3D demoMcGill curl-upBeginner · No equipment

Holds of about 10 s in falling sets of 5, 3 and 1, chin slightly tucked · As in our McGill big 3 routine (editorial). Skip it if bending forward sends pain down a leg, as the move page says

Harder: Crunch

Chest lift (Pilates curl-up) demonstrated on the 3D figure

3D demoChest lift (Pilates curl-up)Beginner · No equipment

8 to 10 reps, resting your head between reps · The move page's dose (a suggested starting point)

Harder: Single-leg stretch (Pilates one leg stretch)

3D demoDead bugBeginner · No equipment

2 sets of 6 to 8 each side · As in our back pain guide (editorial)

Easier: Dead bug heel taps · Harder: Forearm plank

Knee side plank demonstrated on the 3D figure

3D demoKnee side plankBeginner · No equipment

3 holds of 15 to 20 s each side · As in our back pain guide (editorial)

Harder: Side plank

Reverse crunch demonstrated on the 3D figure

3D demoReverse crunchIntermediate · No equipment

2 to 3 sets of 8 to 12, a small curl, a mat under the tailbone · As in our leg raise and abdominal strain guides (editorial). Ease off if repeated bending flares your back, as the move page says

Easier: Cross-body crunch · Harder: Captain's chair knee raise

Half-kneeling Pallof press demonstrated on the 3D figure

3D demoHalf-kneeling Pallof pressBeginner · A band + An anchor point

2 to 3 sets of 8 to 10 each side · As in our back pain guide (editorial)

Harder: Pallof press

Move on when: The curl-up, chest lift and dead bug pass the pain rule for a week, with your back no worse the next morning (editorial).

Follow along: a timer, a cue and the next move, one step at a time.

Stage 3

Back to crunches, then sit-ups

From about week 4 to 8, often later, 2 or 3 core sessions a week: crunches, then sit-ups with your feet free, then your usual ab work, one change at a time by the written steps below. No study has tested a return to sit-ups after back pain, so the order is editorial.

3D demoCrunchBeginner · No equipment

2 sets of 12 to 20, stopping 1 to 3 reps short of failure, feet free, fingertips light at your head · The crunch track of our crunch and sit-up workout (editorial)

Easier: McGill curl-up · Harder: Sit-up (3/4 sit-up)

Sit-up (3/4 sit-up) demonstrated on the 3D figure

3D demoSit-up (3/4 sit-up)Intermediate · No equipment

2 sets of 8 to 15, stopping 1 to 3 reps short, feet free if you can, lowering three-quarters of the way under control · The sit-up track of the same workout (editorial), once 2 sets of 20 crunches are easy, as that workout says

Easier: Crunch · Harder: Jackknife sit-up (V-up)

Forearm plank demonstrated on the 3D figure

3D demoForearm plankIntermediate · No equipment

3 holds of 20 to 45 s · Our plank guide's dose, as our sit-up guide says (editorial)

Easier: Stomach vacuum (drawing-in) · Harder: Plank walk-up

Side plank demonstrated on the 3D figure

3D demoSide plankIntermediate · No equipment

3 holds of 20 to 30 s each side · As in our back pain guide (editorial)

Easier: Knee side plank · Harder: Side plank with leg lift

3D demoBird dogBeginner · No equipment

2 sets of 8 each side, kept twice a week · Editorial

Easier: Bird dog, one limb at a time · Harder: Bear crawl

GHD sit-up (glute-ham developer) demonstrated on the 3D figure

3D demoGHD sit-up (glute-ham developer)Expert · An anchor point

Only if your sport needs it, last: 3 sets of 5 partial-range reps to start, adding range before reps over several weeks · The move page's dose. The move page says avoid it with any current back pain and never do it for reps against a clock

Easier: Jackknife sit-up (V-up)

Move on when: Your usual ab sessions pass the pain rule for 2 weeks. Keep about 60 bending reps a session at most, as our sit-up guide suggests from one expert review, and if a session flares it, go back a stage for a few days, not to nothing (editorial).

Follow along: a timer, a cue and the next move, one step at a time.

What to change for now

Your sit-up for now (written steps)

Our 3D figure can't show all of these. They come from lab studies, a review, NHS pages and our sit-up guide; where a step is our suggestion, it says so. No trial has tested a change to the sit-up for back pain.

1. A crunch or McGill curl-up instead of a full sit-up, curling only until your shoulder blades leave the floor: the lower back bent about 3 degrees in a curl-up against 38 in a full sit-up.
2. Feet free, not hooked under a bar or held by a partner: holding them moved the work from the tummy to the hip flexors in lab studies. Hook them lightly only while you can't come up without it, as our sit-up guide says. No study shows anchoring protects the back, or harms it.
3. A thick mat, or a folded towel under your tailbone and spine on a hard floor, and no rocking or rolling (our suggestion).
4. Curl up and lower slowly, without dropping back, and breathe out as you curl rather than holding your breath.
5. Fingertips light at your temples or arms crossed, never pulling on your head (our neck sit-up guide).
6. Stop 1 to 3 reps short of failure, 2 or 3 days a week; one expert review suggests about 60 bending reps a session at most and a day or two between sessions, which is untested opinion.
7. Leave decline, GHD, weighted and V-up sit-ups and timed tests until the last stage has passed the pain rule (editorial).
8. Keep moving: the NHS says stay active and try to continue with your daily activities, and don't stay in bed for long periods.

Sources 4, 5, 16, 17, 11, 51, 1, 9

Who should change sit-ups for longer

With osteoporosis or a past spinal fracture, swap sit-ups and curl-ups for the dead bug, bird dog and plank, and bend from the hips, as the UK consensus and the Royal Osteoporosis Society advise. After a baby, the NHS says avoid sit-ups to start with and begin with a side-lying tummy draw-in held for a count of 10, up to 10 times; later, curl-ups didn't widen a gap in a trial, so build up and ease off any move that makes the middle of the tummy dome. Later in pregnancy, keep trunk work off your back, as our pregnancy and sit-up guides say.

With a hernia, or after a repair or tummy surgery, follow your surgical team: the NHS says no heavy lifting or strenuous activity for at least 4 to 6 weeks after a groin repair. With back pain that flares with bending or goes down a leg, use the dead bug, bird dog and McGill curl-up while it settles, as our herniated disc and sciatica guides do.

Sources 8, 28, 14, 44, 47, 48, 35

Back to your usual training (written steps)

No study has tested how sit-ups come back after back pain, so these steps are our suggestion unless a source is named.

1. One change at a time: more reps, then the 3/4 sit-up, then full sit-ups, then decline, weighted or GHD sit-ups, then timed tests and challenges.
2. Before a sit-up test that holds your feet and puts your hands behind your head, practise that way for a few weeks with your fingertips touching, never pulling. Core work alone kept soldiers' sit-up test scores up.
3. GHD sit-ups last, from the move page's 3 sets of 5 partial-range reps, adding range before reps over several weeks: big, unaccustomed sessions have been followed by muscle breakdown.
4. Keep two days a week of planks, side planks and bird dogs alongside.
5. If a session flares it, go back a stage for a few days, not to nothing.

Sources 37, 49

Positions to swap, and why

Habit or position	Why it matters	Instead
Full sit-ups while it's sore	More than 3,000 N of modelled compression, much more lower back bend than a curl-up and heavy hip flexor work.	A McGill curl-up or crunch.Try: McGill curl-up
Feet hooked under a bar or held by a partner	It moves the work from the tummy muscles to the hip flexors; no study shows it protects the back.	Feet free, in a crunch for now.Try: Crunch
Decline, banded or weighted sit-ups	The heaviest versions; the banded decline sit-up's move page says leave it out with back pain.	Flat crunches.Try: Crunch
GHD sit-ups for reps or against a clock	The move page says avoid it with current back pain, and big first sessions have been followed by muscle breakdown.	The stage 2 moves, such as the dead bug.Try: Dead bug
V-ups and jackknife sit-ups	Long levers and a fast, loaded bend (our reading, as in our leg raise guide).	A small reverse crunch.Try: Reverse crunch
Sit-ups on a hard floor, rocking on your tailbone	Pressure and rubbing on the tailbone and the bony spine (our reading).	A thick mat or a folded towel, and the chest lift.Try: Chest lift (Pilates curl-up)
Holding your breath and straining through each rep	Two case reports describe a stroke and a spinal bleed during sit-ups with breath-holding.	Breathe out as you curl.Try: McGill curl-up
Hundreds of sit-ups in a challenge	Muscle damage and breakdown have followed sudden, unaccustomed volume.	About 60 bending reps a session at most, and planks for the rest.Try: Forearm plank
Sit-ups with osteoporosis	The UK consensus advises modifying or avoiding repeated or end-range bending of the spine.	Bird dogs, dead bugs and planks.Try: Bird dog
Sit-ups that make the middle of your tummy dome after a baby	The NHS says avoid sit-ups to start with after a birth.	Knee folds and heel slides first.Try: Knee fold
Pushing through pain spreading down a leg	It points to a nerve: see the warning signs and our sciatica guide.	Stop, and keep to gentle moves that don't send pain down the leg.Try: Supine heel slide
Bed rest until it stops hurting	The NHS says stay active and don't stay in bed for long periods.	Walking and the stage 1 moves.Try: Treadmill walking

Routines to follow

Crunch and sit-up workout: from the crunch to the full sit-up

A 15-minute ab workout with a crunch track and a sit-up track, about 60 bending reps at most, plus a side plank and bird dog to balance it.

15 minBeginner10 movesNo equipment

Beginner core workout

A 15-minute beginner core workout on the floor: dead bugs, bird dogs, knee planks, side planks and curl-ups.

15 minBeginner6 movesNo equipment

McGill big 3 core routine

The McGill big three for the core: curl-ups, side planks and bird dogs, each held for 10 seconds at a time in falling sets of 5, 3 and 1 reps.

12 minBeginner3 movesNo equipment

Ab workout (no equipment)

An intermediate ab workout with no equipment: planks, side planks, reverse crunches, hollow holds and mountain climbers.

20 minIntermediate7 movesNo equipment

Diastasis recti workout: a 12-week curl-up programme

A 12-minute tummy routine copied from a trial in women with diastasis recti: head lifts, curl-ups and twisted curl-ups, 5 days a week for 12 weeks.

12 minBeginner5 movesNo equipment

Pilates for back pain (gentle routine)

A gentle 15-minute Pilates-based routine for ongoing low back pain, built from neutral-spine moves with options for backs that dislike bending or arching.

15 minBeginner10 movesNo equipment

More moves for this area

Questions people ask

Why does my lower back hurt when I do sit-ups?

A full sit-up asks your hip flexors to pull your trunk up once your shoulder blades are off the floor, and in a lab model that loaded the lower spine with more than 3,000 newtons. A sore back often complains at that point. A crunch or curl-up with your feet free usually eases it.

Are sit-ups bad for your back?

Not for most healthy backs in sensible doses: in young soldiers, sit-up training caused no more injuries or back pain than core exercises. They do load the lower back more than crunches, so swap them while your back is sore. With osteoporosis, UK guidance says use other trunk exercises.

Why does my tailbone hurt when I do sit-ups?

Usually the tailbone pressing and rolling on a hard floor, though no study has counted it. Use a thick mat or a folded towel, curl only to your shoulder blades and don't rock. If it hurts to sit for weeks afterwards, or started after a fall, our tailbone pain guide covers it.

Why does the bone in my lower back hurt during sit-ups?

The bony bumps down the middle of your spine take your weight as you roll on the floor, and the skin over them can get rubbed. Padding and a smaller range usually fix it (our suggestion). A sore spot that is swollen, hot or there without sit-ups needs a GP.

Should I anchor my feet when doing sit-ups?

Leave them free if you can: holding them let the hip flexors do more and the tummy muscles less in lab studies. Hook them lightly only while you can't come up without it. No study has measured whether anchoring changes the load on your back.

Why do decline or GHD sit-ups hurt my back?

They add range and load to a move that already loads the lower back heavily, though no study has measured them. Leave them until flat sit-ups pass the pain rule. Start GHD sit-ups with short, partial reps and never do them for reps against a clock.

Are crunches better than sit-ups for back pain?

For a sore back, yes: a curl-up bent the lower back 3 degrees against 38 in a full sit-up, and partial curl-ups gave the most ab work for the least spine load. Crunches still train the six-pack hard.

Can I do sit-ups with a herniated disc or sciatica?

If bending forward sends pain down your leg, leave them out for now and use the dead bug and bird dog. Disc bulges are common in people without pain and many shrink on their own. Our herniated disc and sciatica guides cover it.

Could it be a hernia?

A lump in the groin, at the top of the thigh or near the belly button that gets bigger when you strain and smaller lying down can be: see a GP. A painful hernia with sickness, a bloated tummy or no wind or poo needs urgent help, as the warning signs say. A ridge down the middle of the tummy after pregnancy is usually a gap between the muscles.

Do I need a scan?

Not usually: NICE doesn't routinely offer imaging for back pain, and disc changes are common in people without pain. The warning signs need urgent assessment instead.

How long will it take?

Most new back pain eases a lot within 6 weeks, though no one can promise a date. Many people keep training with changed ab work throughout.

When should I see a doctor?

Call 999 for numbness around your genitals or bottom, new bladder or bowel trouble, or weakness in both legs. Get a same-day check for back pain with a fever, after an injury, or a painful hernia with sickness, and see a GP if it isn't better after a few weeks or a lump appears. In the US, call 911 where this page says 999.

Related exercise guides

Other pain guides

Sources

Exercise education, not a diagnosis or treatment plan. It is written from the guidelines and studies listed above; review by a clinician is pending. If your pain follows an injury, is severe, is getting worse, or comes with any warning sign listed on this page, get it assessed. Health disclaimer.