Exercise guide
You can exercise while breastfeeding. It doesn't reduce your milk supply, change the quality of your milk or slow your baby's growth: the UK Chief Medical Officers say you can be active while breastfeeding, and trials and a 2025 review of 46 studies agree. Only all-out efforts change your milk at all, by briefly raising the lactic acid in it.
Most of what matters is practical: feeding or expressing before you exercise, a supportive bra that doesn't squeeze, eating and drinking enough, and losing weight slowly if you want to. Breastfeeding doesn't change when you can start exercising after the birth; our postpartum guide covers that timeline.
This guide covers milk supply and lactic acid, feeding first, sports bras and blocked ducts, food, drink and weight loss, strength training and your bones, running and your pelvic floor, caffeine and supplements, mastitis, and the warning signs that need your midwife, health visitor or general practitioner (GP).
Regular exercise doesn't reduce your milk supply or change its quality, and it doesn't slow your baby's growth. The UK Chief Medical Officers say you can be active while breastfeeding: aim for at least 150 minutes of moderate activity a week, build back up to muscle strengthening twice a week, and do pelvic floor exercises every day.
Feeding or expressing shortly before you exercise makes it more comfortable, as the American College of Obstetricians and Gynecologists (ACOG) advises, and the UK running guideline suggests planning feeds so your breasts aren't too full when you run. It also sidesteps the question of lactic acid, which rises in milk only after all-out efforts.
Your back and cup size are likely to have changed, so the National Health Service (NHS) suggests getting measured for a new sports bra. Choose support rather than compression: a tight bra, a bag strap or tight clothing pressing on the breast can cause a blocked milk duct.
You don't need a special diet. UK reference values add about 330 calories (kcal) a day for the first 6 months of exclusive breastfeeding. Keep a drink beside you when you feed, but drinking extra water beyond your thirst won't make more milk.
If you're breastfeeding and overweight, the NHS suggests a healthy, balanced diet and regular, moderate exercise, such as a brisk 30-minute walk each day, and says this won't affect the quality or quantity of your milk. In a trial, losing about 0.5 kg a week from 4 weeks after the birth didn't affect babies' growth. Avoid crash diets.
If a breast becomes hot, tender or swollen and you feel achy or as if you have flu, the NHS advice is to carry on breastfeeding, rest, and contact your GP or NHS 111 if you feel worse at any time or are no better within 12 to 24 hours. Go back to exercise once you feel better (our suggestion).
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Milk supply follows demand. The NHS's ways to boost it are feeding your baby as often and for as long as they want, offering both breasts at each feed, and expressing after feeds once breastfeeding is established. The things it lists as affecting supply include poor attachment, not feeding often enough, alcohol, smoking, some medicines, illness, and anxiety, stress or depression. Exercise isn't on the list.
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UK reference values add 330 kcal a day for the first 6 months of exclusive breastfeeding. Other sources give higher figures: a 2026 sports medicine review says 450 to 500 kcal, and La Leche League GB 500 to 700. The NHS says you don't need a special diet, just a healthy, varied one.
Breastfeeding draws calcium into your milk, about 200 mg a day, and bone density at the spine can fall by 3% to 9% over 6 months. It's temporary: across 32 studies, bone recovered once periods returned and after weaning, though in one study a quarter of women hadn't fully regained it by 19 months.
The NHS says your ligaments and joints are more supple for a few months after the birth, so take care not to stretch or twist too much. Breastfeeding keeps oestrogen low for longer, but the UK running guideline says the theory that hormones such as relaxin loosen joints enough to cause injury after the birth hasn't been proven.
In a trial of 33 breastfeeding women, 45 minutes of aerobic exercise 5 days a week for 12 weeks, starting 6 to 8 weeks after the birth, didn't change milk volume or composition, the babies' weight gain or the milk hormone prolactin, and raised fitness by 25%. In a smaller study, 8 women who exercised hard made milk with the same energy, fat, protein and lactose as 8 inactive women, and ate more.
A 2025 review of 46 studies found milk quality and quantity, babies' growth and development, and injuries no different with exercise. ACOG and the 2025 Canadian guideline say the same.
Across 4 small trials with 170 women, mothers' exercise made no difference to breastfed babies' weight gain, though the authors call the evidence limited. In 587 mothers followed for a year in Perth, Australia, exercise wasn't linked with stopping breastfeeding or with the babies' growth.
Lactic acid in milk rose after maximal exercise, and after hard exercise at about 15 out of 20 for effort, but not after moderate exercise. In 26 women, mothers rated their babies as less keen on milk expressed 10 to 30 minutes after a maximal exercise test.
In a later study of 24 women, milk expressed an hour after a maximal test or 30 minutes of moderate exercise was given by bottle, and neither the mothers nor 3 lactation consultants who didn't know which milk was which saw any difference in how the babies took it.
An antibody in milk, immunoglobulin A (IgA), fell for 10 to 30 minutes after an exhausting treadmill test in 17 women and was back to normal within an hour. In 53 women, this antibody and other immune factors didn't differ with fitness, and 30 minutes of moderate exercise didn't change them.
A study in women and mice linked exercise with more of a milk sugar called 3'-sialyllactose, but a 2025 trial in 20 women found no clear change after one moderate or hard session. In another trial of 20 women, hard intervals briefly raised a compound called adiponectin. What these changes mean for babies, if anything, isn't known.
In 40 overweight women who were exclusively breastfeeding, eating 500 kcal a day less and exercising for 45 minutes 4 days a week from 4 weeks after the birth took off 4.8 kg in 10 weeks, against 0.8 kg, with no difference in the babies' weight gain or length. In 67 women, an 11-day cut of 35% in energy, by diet or by diet plus exercise, didn't change milk volume or composition, and with exercise the weight lost was nearly all fat.
Across 12 trials after childbirth, diet plus exercise took off about 1.9 kg more than usual care, while exercise alone made little difference to weight. The trials were small and of mixed quality.
In a review of 45 studies, 63% found little or no link between breastfeeding and weight change, though 4 of the 5 best-quality studies found one. Across 14 cohorts, mothers who breastfed kept on 0.38 kg less on average.
In 20 women randomised 4 weeks after the birth, weight-bearing aerobic exercise 3 days a week plus strength training 3 days a week for 16 weeks cut bone loss at the spine to 4.8%, against 7.0%. In 27 women, eating 500 kcal a day less plus strength training brought more weight loss with no difference in bone loss. Two trials combined, with 55 women, found the difference at the spine still there a year after the birth. Pooled, exercise saved about 1.6% of bone density at the spine, but the certainty is low.
A Cochrane review found no good randomised trials of drinking extra to make more milk; in the one old study of 210 women, advice to drink more didn't raise milk production. La Leche League GB says supply isn't linked to how much water you drink.
Joints do loosen in pregnancy: in one study, 19 of 35 women had more laxity at the wrist by the third trimester, and in another, laxity rose in 5 of 7 joints through pregnancy and after the birth. But neither study found that the laxity tracked relaxin or other hormone levels, and the UK running guideline says the injury theory hasn't been proven.
We found no study of sports bras in breastfeeding women. In 20 women with large breasts who weren't breastfeeding, a bra that lifted and compressed the breasts reduced discomfort during exercise, while the UK running guideline suggests support rather than compression. The Academy of Breastfeeding Medicine advises a well-fitting, supportive bra, based on lower-level evidence.
From ACOG's advice to feed or express first and to drink before you start, the UK running guideline's advice on timing feeds and on support rather than compression, the NHS on what causes a blocked duct, La Leche League GB's advice to take tighter bras off after exercise, and trials in which exercising mothers ate more. Planning long sessions around feeds is our suggestion.
"Do not rely on your pre-pregnancy sports bra," says the NHS: your back and cup size are likely to have changed, so get measured for a new one. Choose more support for running and jumping (our suggestion), and see our women's guide on how much a sports bra cuts breast movement.
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The UK running guideline suggests a personally fitted sports bra that gives support rather than compression. La Leche League GB says to make sure your chest isn't compressed, and to take tighter bras off soon after exercise. For full, sore breasts (engorgement), the NHS suggests a well-fitting breastfeeding bra that doesn't restrict your breasts.
A blocked milk duct can be caused by something pressing on the breast, such as a tight bra, a bag strap or tight clothing, as well as by skipping or delaying a feed. You may feel a small, tender lump. The NHS advice is to carry on feeding and to avoid tight clothes or bras so your milk can flow freely.
The NHS says you can start gentle exercise as soon as you feel up to it: walking, gentle stretches and pelvic floor exercises. Get advice at your 6-week postnatal check before high-impact exercise such as aerobics or running. Breastfeeding doesn't change this timeline.
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Your recovery will take longer. The NHS says to talk to your midwife, health visitor or GP before starting anything strenuous. Our caesarean guide covers lifting and the first weeks.
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The UK Chief Medical Officers suggest at least 150 minutes of moderate activity a week, building back up to muscle strengthening twice a week, and pelvic floor exercises every day. The 2025 Canadian guideline suggests at least 120 minutes of moderate to vigorous activity over 4 or more days a week, and lists breastfeeding among things that may need support, not reasons to avoid activity.
The NHS says to wait until 7 days after your postnatal bleeding has stopped.
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The UK running guideline suggests waiting until about 3 months after the birth, and passing its checks first: walking, hopping and jogging on the spot without leaking, heaviness or pain. It lists breastfeeding among the things that may mean a slower return. Feed first and wear a supportive bra.
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The NHS says you don't need a special diet while breastfeeding, just a healthy one with a variety of foods. UK reference values add 330 kcal a day for the first 6 months of exclusive breastfeeding, and our calories per day calculator adds this for you.
Have a drink beside you when you settle down to feed (NHS), and drink before you exercise (ACOG). Then drink to your thirst: extra water won't make more milk.
The NHS: "If you're breastfeeding and you're overweight, the best way to lose weight is by eating a healthy, balanced diet and taking regular, moderate exercise, such as a brisk walk for 30 minutes each day. This will not affect the quality or quantity of your breast milk."
In a trial, about 0.5 kg a week from 4 weeks after the birth was safe for babies' growth. La Leche League GB suggests around 400 to 500 g a week and at least 1,800 kcal a day, and a 2026 review links eating under 1,500 kcal a day with less milk. No UK guideline sets a minimum, so lose weight gradually and avoid crash diets.
If you join one, the NHS says to tell them you've recently had a baby and that you're breastfeeding, so they can give you the right advice.
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Breastfeeding uses energy, but most studies find little link between breastfeeding and losing weight. Food and activity together are what work.
The bone you lose while breastfeeding comes back, and strength work may slow the loss: in one small trial, weight-bearing aerobic exercise plus strength training 3 days a week cut the loss at the spine from 7.0% to 4.8%. The certainty is low, but strength work helps you lift and carry a growing baby too.
Build back up to strength work twice a week. The UK running guideline suggests squats, lunges and bridges from about 2 to 4 weeks after a straightforward birth, in line with everyday tasks, and deadlift practice from about 6 to 8 weeks, starting no heavier than your baby in a car seat and building up gradually.
Breastfeeding isn't a reason to avoid weights. For the first few months, take care not to stretch or twist too far (NHS), and build the load up gradually (UK running guideline).
Follow the same timeline as anyone after the birth: about 3 months and the readiness checks first, then build up slowly. Breastfeeding may mean a slower start. Feed first, wear a supportive bra, and ease off if you notice leaking, heaviness or pain.
Postnatal classes are a good start, and the NHS says to tell the instructor of any class that isn't a postnatal class that you've recently had a baby. Lying face down can be uncomfortable with full or tender breasts, so feed first or swap those poses (our suggestion). Hot yoga adds heat and sweat: drink to thirst, and leave the room if you feel faint (our suggestion).
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The NHS: "while feeding your baby, sit with your back well supported and straight. Put a small pillow or cushion behind your waist to support your lower back. Make sure your feet can reach the floor."
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Kneel or squat for low tasks such as picking up toys or bathing your baby, change nappies on a raised surface, bend your knees and keep your back straight when lifting, and hold heavy things close. Carry your baby in a well-fitting sling, and set the pram or buggy handles so your elbows are bent at right angles.
Long spells looking down at a feeding baby can leave your neck and upper back stiff. The neck and upper back moves below suit a break between feeds (our suggestion), and our neck pain and upper back pain guides cover the warning signs. See your GP if back pain doesn't settle.
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Start with about 10 minutes of walking after the birth and add a few minutes each day, as our easy cardio workout suggests, building towards a brisk 30 minutes most days (NHS). The elliptical trainer and recumbent bike pages' dose is 10 to 20 minutes at a moderate effort to start, building towards 30. The UK running guideline suggests a static bike or cross-trainer from about 4 to 6 weeks, once sitting on a saddle is comfortable. Swim once your bleeding has stopped for 7 days, and run from about 3 months.
3D demoTreadmill walkingBeginner · Cardio machine
3D demoElliptical trainerBeginner · Cardio machine
3D demoRecumbent exercise bikeBeginner · Cardio machine
3D demoStationary cyclingBeginner · Cardio machine
Front crawl (freestyle swimming)Intermediate · Other / check instructions
3D demoTreadmill joggingIntermediate · Cardio machineThe pelvic floor exercise page's dose: start with 8 slow holds of up to 10 seconds and 8 quick squeezes, three times a day, building towards 10 of each. The side-lying tummy draw-in page's: hold for up to 10 seconds, up to 10 times. Lateral breathing: 5 to 8 breaths at the start of a session; slow breathing: at least 5 minutes, regularly (both the move pages' doses).
Between feeds, sitting or standing: chin tucks, 10 slow reps, and the doorway chest opener, 45 seconds (from our neck and shoulder stretches workout); thoracic rotation, 6 per side, cat-cow, 8 slow waves, and the upper trap release, 2 slow holds of 30 seconds per side (the move pages' doses).
Our editorial starting point is 2 sets of 8 to 12 for the leg and pulling moves, 8 reps for sit-to-stands and wall push-ups and 10 bridges (as in our 10-minute starter workout), 5 to 8 bird dogs and 6 dead bug heel taps each side, stopping if the middle of your tummy domes. The band row page's dose is 3 sets of 10 to 15 once you're ready. Start deadlift practice no heavier than your baby in a car seat (UK running guideline), keep carries light at first, and do any face-down work after a feed (our suggestions).
3D demoSit to stand from a chairBeginner · A bench or box
3D demoBodyweight squatBeginner · No equipment
3D demoGlute bridgeBeginner · No equipment
3D demoWall push-upBeginner · A wall
3D demoBand rowBeginner · A band + An anchor point
3D demoBand pull-apartIntermediate · A band
3D demoKettlebell deadliftBeginner · A kettlebell
3D demoDumbbell goblet squatIntermediate · A dumbbell
3D demoSuitcase carryIntermediate · A dumbbell + A kettlebell
3D demoBird dogBeginner · No equipment
3D demoDead bug heel tapsBeginner · No equipmentThe postnatal exercises suit the first weeks, and the postnatal strength workout follows from about 6 weeks; its tips already say to feed or express first and wear a supportive bra. The daily pelvic floor workout starts with crocodile breathing, face down: do it on your side or after a feed if your breasts are full. Running waits for the readiness checks, from about 3 months.
A gentle 25-minute routine for the first weeks after birth: pelvic floor, breathing, tummy and hip exercises on the floor, sit-to-stands and a walk.
25 minBeginner12 movesA bench or box, Cardio machineA steady 30 to 45 minute cardio session at talk-but-not-sing pace: walk, cycle, row or cross-train, counting toward weekly activity guidelines.
40 minBeginner3 movesCardio machine, A wallA 5-minute daily pelvic floor workout for women and men: slow holds and quick squeezes, three times a day, with how to find the right muscles.
5 minBeginner2 movesNo equipmentEight gentle neck and shoulder stretches for desk stiffness, done standing or seated in ten minutes.
10 minBeginner8 movesA wallA 25-minute strength workout from about 6 weeks after birth: sit-to-stands, deadlift practice, push-ups, rows, bridges and tummy work, with the knack.
25 minBeginner14 movesA bench or box, A kettlebellA gentle 20-minute beginner home workout with a chair, a wall and a band: sit-to-stands, wall push-ups, band rows, step-ups and dead bugs.
20 minBeginner11 movesA bench or box, A wallThe UK return-to-running checks after birth as a 25-minute session: balance, single-leg squats, hops and bounds, then strength tests aiming for 20.
25 minIntermediate14 movesCardio machine, A wallA 30-minute beginner run-walk session: a brisk walk, then 1-minute jogs with 1-minute walks, building to 3-minute runs over your first three weeks.
30 minBeginner5 movesCardio machine, A wallFor week-by-week structure from the first days to running and lifting.
A postpartum workout plan from the first days after birth to running and lifting again, week by week, with a caesarean track and readiness checks.
5 training days25 minBeginner6 days a weekA free 8-week walking plan for beginners: build to 150 minutes of brisk walking a week, with intervals, hills and two short strength sessions.
6 training days40 minBeginner3 days a weekA 9-week beginner plan with the same walk-to-run shape as Couch to 5K: three run-walk sessions a week, from 1-minute jogs to 30 minutes of running.
3 training days35 minBeginnerThe NHS recommends no more than 200 mg of caffeine a day while breastfeeding: a mug of coffee has about 90 mg and a 250 ml can of energy drink about 80 mg. Caffeine can reach your baby through your milk and may make them restless. Count any caffeine in pre-workout drinks too (our suggestion).
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Creatine is a normal part of breast milk, but no one has measured what supplements do to milk levels. LactMed, the US drugs and breastfeeding database, says: "Until more data are available, it is probably best to avoid creatine supplementation unless it is prescribed by a healthcare professional."
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Tell your pharmacist or GP that you're breastfeeding whenever you discuss a medicine. The NHS says not enough is known about herbal remedies to be sure they're safe while breastfeeding, and not to stop taking prescribed medicines without talking to your GP.
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Mastitis is inflammation in the breast, often after a blocked duct isn't relieved. Symptoms include a breast that feels hot and tender, a swollen area that may feel hot and painful (redness can be harder to see on black or brown skin), feeling achy, tired and tearful or as if you have flu, and a high temperature.
Carry on breastfeeding, as stopping suddenly makes it worse. Let your baby feed on the tender breast first, ask your midwife, health visitor or a breastfeeding specialist to watch a feed, and get as much rest as you can. Contact your GP or NHS 111 if you feel worse at any time, or if you're no better within 12 to 24 hours.
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The Academy of Breastfeeding Medicine advises against deep massage of the breast and against pumping to "empty" it beyond what your baby needs; the NHS says to express only as much as your baby would usually need. The Academy also notes that the hot flushes and sweats that are common after the birth can feel like a fever.
Rest while you feel unwell, then start again gently once you feel better (our suggestion). If a breast becomes painful, hot or lumpy during exercise, stop, feed or express, and treat it as a possible blocked duct.
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This is general information, not a diagnosis. In the US, call 911 where this page says 999.
Call 999, and don't drive yourself to accident and emergency (A&E), if:
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Call 999 if an adult:
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The National Institute for Health and Care Excellence (NICE) says these can be signs of a serious problem after the birth. Contact your midwife or GP the same day, or NHS 111:
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If you're worried about how you're feeling, feel you're struggling to cope, or think you may be depressed: effective help is available. Ask for help early, too, with sore nipples or worries about whether your baby is getting enough milk. The National Breastfeeding Helpline is on 0300 100 0212.
Stop and drop back if exercise brings on leaking, heaviness, a dragging feeling or pain, or if your bleeding gets heavier or turns red again; see your GP or a pelvic health physiotherapist if it carries on. A breast that turns painful, hot or lumpy needs feeding or expressing and a rest.
Trials and a 2025 review of 46 studies found no difference in milk supply, milk quality or babies' growth with exercise.
Lactic acid rises only after all-out efforts, and briefly. When milk from an hour after hard or moderate exercise was given by bottle, babies took it just as well. None of the guidance we read says to throw milk away; feeding first avoids the question.
Drink to thirst and keep a drink nearby when you feed. In the one trial of advice to drink extra, milk production didn't rise.
Most studies find little link between breastfeeding and weight loss. Diet and exercise together are what work.
Losing about 0.5 kg a week with a modest calorie cut and exercise didn't affect babies' growth or milk in trials. Crash diets are a different matter.
The UK running guideline says that theory hasn't been proven. Strength work twice a week is recommended after the birth, and in one trial, strength training with weight-bearing exercise slowed breastfeeding bone loss.
We found no study linking the two. Pressure from a tight bra or strap, or a skipped feed, can block a duct, so wear support that doesn't squeeze and feed first.
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The Academy of Breastfeeding Medicine advises against deep massage and pumping beyond your baby's needs, and the NHS says to express only as much as your baby would usually need.
No. Regular exercise doesn't reduce your milk supply or the quality of your milk, or slow your baby's growth: trials and a 2025 review of 46 studies agree. What matters for supply is feeding often, so plan long sessions around feeds rather than skipping one.
Only after all-out efforts, and only for a short time: lactic acid in milk rose after maximal exercise but not after moderate exercise. In one small study babies took milk from just after a maximal test less readily, but milk from an hour later made no difference. You don't need to throw milk away; feeding before a hard session avoids the question.
Yes, if you can. Feeding or expressing first avoids uncomfortable full breasts, and the UK running guideline suggests planning feeds so your breasts aren't too full when you run. It may also give you a little longer before the next feed.
Breastfeeding doesn't change the timing. After a straightforward birth, you can start walking, gentle stretches and pelvic floor exercises as soon as you feel up to it, and get advice at your 6-week check before high-impact exercise. Running usually waits until about 3 months.
A supportive, well-fitted one that doesn't squeeze: get measured, as your size has probably changed, and choose support rather than compression. Tight bras and bag straps can press on the breast and cause a blocked duct, so take a tight sports bra off soon after exercise. A nursing sports bra is handy but not essential.
Yes, if it's gradual. The NHS suggests a healthy, balanced diet and regular moderate exercise, such as a brisk 30-minute walk each day, and says this won't affect the quality or quantity of your milk. In a trial, about 0.5 kg a week from 4 weeks after the birth didn't affect babies' growth; avoid crash diets.
UK reference values add 330 kcal a day for the first 6 months of exclusive breastfeeding, and some other sources give 450 to 700. If you're also training hard, you may need more: in trials, women who exercised ate more. Our calories per day calculator adds the 330 kcal for you.
Drink before you start, keep a drink beside you when you feed, and drink to your thirst. Drinking extra beyond that won't make more milk.
Yes, once you're ready after the birth. The UK guideline suggests waiting until about 3 months and passing its readiness checks, and says breastfeeding may mean a slower start. Feed first and wear a supportive bra.
Yes. UK guidance is to build back up to strength work twice a week, and in one small trial strength training plus weight-bearing exercise slowed the temporary bone loss of breastfeeding. Start light, for example deadlifts no heavier than your baby in a car seat, and build up gradually.
Keep caffeine to no more than 200 mg a day in total, as the NHS advises, and count what's in a pre-workout drink. The drugs and breastfeeding database LactMed suggests avoiding creatine supplements unless a health professional prescribes them, because their effect on milk hasn't been measured. Ask a pharmacist before taking any supplement.
Rest first: the NHS advice is to get as much rest as you can and carry on breastfeeding. Contact your GP or NHS 111 if you feel worse at any time or are no better within 12 to 24 hours. Go back to exercise gently once you feel better.
Exercise education, not a diagnosis or treatment plan, and clinical review of these guides is pending. Stop and get advice for chest pain, unusual breathlessness, dizziness or fainting, or new pain, and check with your doctor or midwife first if they have told you to limit activity. Health disclaimer.
