Reviewed by The Mom Store editorial team, October 2026. See our editorial policy.
The main ab exercises to avoid in pregnancy are sit ups, crunches and moves like them that curl your trunk forward against your bump, plus anything that has you lying flat on your back for more than a few minutes later in pregnancy. Gentle deep tummy work, pelvic floor exercises and regular walking are the usual alternatives. If you have a pregnancy complication, ask your doctor what is right for you before you start.
Why your abdominal muscles need different exercise now
As your bump grows, the connective tissue down the middle of your tummy, between the two long abdominal muscles, stretches and becomes thinner and wider. This is called diastasis rectus abdominis. The UCLH NHS physiotherapy advice on diastasis rectus abdominis says up to a third of women have it by the second trimester and almost all women by the end of the third. So it is very common and not a sign you have done something wrong. You may notice your tummy rising into a ridge or "dome" down the middle during some movements.
This is why NHS physiotherapists, such as the UCLH team, advise changing the kind of tummy exercise you do rather than training harder through it.
What to avoid
- Sit ups and crunches, and moves like them. UCLH advises avoiding sit ups, stomach crunches or similar exercises unless your physiotherapist guides you. That family includes bicycle crunches, V ups, Russian twists with your feet off the floor and weighted sit up twists. The Whittington Health NHS leaflet on exercise during pregnancy goes further and says not to do sit ups until six weeks after giving birth.
- Long stretches on your back. The NHS guide to exercise in pregnancy says that in later pregnancy you should avoid any activity that involves lying flat on your back for more than a few minutes, because it can make you dizzy and is not good for your baby. Leg raises and floor ab routines done on your back fall into this group.
- High impact and contact. The Whittington leaflet advises avoiding contact sports and high impact exercise, and the NHS lists sports with a risk of falling or being hit in the bump.
- Starting something hard and new. The NHS does not recommend taking up a new vigorous activity, such as running, in pregnancy. Pregnancy is a time to keep up what you already do in a gentler form, not to begin a tough core programme.
Planks, ab wheel rollouts and mountain climbers are not covered in the NHS guidance linked here. If they were part of your routine before pregnancy, ask a physiotherapist whether and how to adapt them, and stop if you see doming along the middle of your tummy.
What to do instead
Deep tummy drawing in
This is the exercise both NHS leaflets describe. Lie on your side, which is easiest, or sit or stand. Gently draw your lower tummy, below your belly button, in towards your spine, as if tucking it into a snug belt. Hold for up to 10 seconds while breathing normally, then relax. The Whittington leaflet suggests 10 repetitions, four to six times a day. Do not brace your whole tummy or hold your breath. Once this feels easy, UCLH suggests keeping the muscles drawn in while you lift one arm, then extend one leg.
Pelvic floor exercises
Squeeze and lift the muscles around your back passage, vagina and front passage, as UCLH describes them. The Whittington leaflet describes slow holds of up to 10 seconds, repeated 10 times, followed by 10 quick squeezes, four to six times a day. It also suggests tightening them before you cough, sneeze or lift.
Everyday movement
The NHS recommends about 150 minutes of moderate intensity activity a week in pregnancy, plus muscle strengthening on two days. Any activity is better than none. Soft, stretchy maternity pants that sit under or over the bump make walking and floor work more comfortable.
Protect your midline through the day
UCLH suggests getting out of bed by bending your knees, rolling onto your side and pushing up with your arms, rather than sitting straight up. Bend down on one knee to lift, and avoid straining on the toilet.
When to stop and get medical advice
The Whittington leaflet says to stop exercising and get medical advice if you have very strong shortness of breath, chest pain or a racing or irregular heartbeat, dizziness, painful contractions, pain in your tummy or pelvis, vaginal bleeding, leaking fluid, pain or swelling in your calf, your baby moving less than normal, or extreme tiredness. The NHS also says to stop if you feel uncomfortable, too hot or unwell, and not to exercise on an empty stomach.
After the birth, if the gap or doming does not seem to be improving, UCLH advises asking your doctor for a referral to a physiotherapist.
This article is general information and does not replace advice from your doctor.
