Exercising While Breastfeeding: What Every Active Mum Needs to Know

Is It Safe to Exercise While Breastfeeding?

This is the question most new mums ask first, and the answer is straightforward: yes. The Australian Breastfeeding Association and the American College of Obstetricians and Gynecologists (ACOG) both support exercise during breastfeeding.

The concern many women have is that exercise will reduce their milk supply or make their milk taste different. Here's what the evidence actually says:

• Milk supply is not affected. According to the Australian Breastfeeding Association, moderate and aerobic exercise has no effect on breastmilk supply, nutrients (fat, protein, lactose), immune factors, or mineral levels. A landmark study published in the New England Journal of Medicine (Dewey et al., 1994) found that women exercising 45 minutes a day, five days a week showed no change in milk volume or composition.
• Milk composition stays the same. ACOG's Committee Opinion No. 804 confirms that "regular aerobic exercise in lactating women has been shown to improve maternal cardiovascular fitness without affecting milk production, composition, or infant growth." Earlier concerns about lactic acid changing milk taste have not been supported by recent research.
• Baby's growth is unaffected. Babies of exercising mothers gain weight at the same rate as babies of sedentary mothers.

The one thing exercise does affect is how you feel. A 2022 meta-analysis published in BMC Public Health found that at least 90 minutes of physical activity per week can significantly reduce the risk of postpartum depression. ACOG describes physical activity as "an essential factor in the prevention of depressive disorders of women in the postpartum period." Better sleep, improved mood, and more energy - all of which make the early months of motherhood more manageable.

You're Not Choosing Between Being a Mum and Being Yourself

Here's what nobody tells you: the hardest part of exercising while breastfeeding isn't the exercise itself. It's the guilt. The feeling that taking 30 minutes for yourself means you're not giving your baby everything they need.

But staying active isn't selfish - it's how you show up as a better, more energised version of yourself for your baby. The evidence backs this up. And the practical barriers? They're smaller than they feel:

• "I don't have time to change bras three times a day." A nursing sports bra works for the gym, the school run, and feeding on the couch. One bra, all day.
• "My body doesn't feel like mine anymore." Your breasts have changed size (sometimes more than once). A bra with multiple hook-and-eye closures adjusts with you instead of making you buy a new one every few weeks.
• "I'm worried about blocked ducts or mastitis from tight bras." Wire-free structured cups give you high-impact support without compressing the milk ducts that underwire presses against.
• "I leak when I exercise and it's embarrassing." Moisture-wicking fabric manages sweat and milk leaks before they show through your top. Pair it with breast pads for extra confidence.
• "I just want to feel like me again, not like a walking milk machine." Getting back into your workout routine - in gear that actually works - is one of the first things that makes you feel like yourself again.

When Can You Start Exercising After Having a Baby?

There's no single answer because it depends on your birth experience, but here's a general timeline based on ACOG and Australian Government guidelines:

Vaginal birth: ACOG notes that "some women are capable of resuming physical activities within days of delivery." Light walking and pelvic floor exercises can start within the first week. Most women feel ready for moderate exercise (swimming, cycling, strength training) by 4-6 weeks. High-impact exercise like running is typically safe from 6-12 weeks, depending on pelvic floor recovery.

Caesarean birth: Walking is fine once you're mobile, but your abdominal incision needs time to heal. Most obstetricians recommend waiting 6-8 weeks before moderate exercise and 10-12 weeks before anything high-impact. Listen to your body and get clearance from your doctor or midwife.

How much? Both ACOG and the Australian Government Department of Health recommend 150 to 300 minutes (2.5 to 5 hours) of moderate-intensity physical activity per week for postpartum women. That's about 30 minutes a day, five days a week - and it doesn't have to be all at once.

Your 6-week postnatal check is a good milestone. Raise exercise with your GP or obstetrician at that appointment - they can assess your pelvic floor and core, and flag anything you should modify. Only 36% of women report receiving advice on physical activity in the first three months postpartum (Evenson et al., Journal of Women's Health), so don't wait for your doctor to bring it up.

Best Types of Exercise While Breastfeeding

There's no exercise that's off-limits simply because you're breastfeeding. The limiting factor is your postpartum recovery, not your milk. That said, some activities are easier to manage around feeds and naps than others.

Works well for breastfeeding mums:

• Walking and pram walks - no childcare needed, easy to fit around feeds
• Strength training - rebuild core and glute strength lost during pregnancy
• Swimming and aqua aerobics - low impact, easy on joints still affected by relaxin (which can take up to 12 months to return to pre-pregnancy levels, according to Cleveland Clinic - longer if you're breastfeeding)
• Yoga and pilates - focuses on core and pelvic floor recovery (look for postnatal-specific classes)
• Running - once cleared by your physio or GP (usually 12 weeks minimum for pelvic floor readiness)
• HIIT and gym sessions - fine once you've rebuilt baseline fitness, just feed or express beforehand if fullness is uncomfortable

Practical tip: Feed your baby (or express) before you exercise. Full breasts during high-impact movement are uncomfortable and can lead to blocked ducts. Exercising after a feed means your breasts are lighter and you have a window before the next feed.

What to Wear: Nursing Sports Bra vs Regular Sports Bra

This is where most breastfeeding mums hit a practical wall. Your pre-pregnancy sports bras probably don't fit (breasts can increase 1-2 cup sizes during breastfeeding, and keep changing month to month). Even if they did, getting a compression sports bra off to feed a hungry baby at the gym, the park, or mums' group is not realistic.

Can you use a regular sports bra while breastfeeding? Technically, yes. But you'll need to fully remove it or struggle to pull it up every time your baby needs to feed. For mums who are exercising regularly, the daily routine looks like this: nursing bra for the morning feed, switch to sports bra for gym, switch back to nursing bra, change again for bed. That's three bra changes before lunch.

A nursing sports bra collapses all of that into one. Drop-down cups or clips give you one-handed feeding access without removing the bra. You get the support you need during exercise and the access you need for breastfeeding - gym to feed to school run, no bra change required.

What to look for in a nursing sports bra:

Feature	Why It Matters	The Problem It Solves
Drop-down nursing clips	One-handed feeding access without removing the bra	"I can't get my sports bra off to feed at the gym"
Wire-free structured cups	Support without pressure on sensitive breast tissue or milk ducts	"I'm worried about blocked ducts from tight bras"
Moisture-wicking fabric	Keeps sweat and milk leaks away from skin to prevent irritation	"I leak during exercise and it shows through my top"
Racerback or crossback design	Distributes weight for stability during high-impact movement	"My breasts bounce painfully when I run"
Multiple hook-and-eye closures	Adjusts as your breast size fluctuates throughout your breastfeeding journey	"My size keeps changing and nothing fits for long"

The Cake Maternity Popcorn Nursing Sports Bra ticks all of these boxes. It's designed for high-impact exercise with wire-free structured cups and a bounce panel for stability, moisture-wicking spacer fabric, and dropdown nursing clips for quick feeding. The racerback design locks everything in during running, HIIT, and gym sessions. Six hook-and-eye options mean it adjusts as your body changes - so you're not replacing it every few weeks. Available in sizes 10-22, cups B-GG.

Tips for Exercising Comfortably While Breastfeeding

1. Feed or express before you exercise. Lighter breasts mean less bouncing and more comfort during movement.
2. Stay hydrated. You're already producing milk, which uses extra fluid. Add exercise and your hydration needs increase. Keep water with you and drink before, during, and after.
3. Wear breast pads if you leak. Some women leak during exercise, especially in the early months. Disposable or reusable breast pads inside your nursing sports bra catch leaks before they show through your top.
4. Start slowly and build up. Your ligaments are still looser than normal due to relaxin, which can take up to 12 months to return to pre-pregnancy levels and may last even longer if you're breastfeeding (Cleveland Clinic). Ease back into high-impact exercise rather than jumping straight to pre-pregnancy intensity.
5. Don't ignore pain. Pelvic floor heaviness, leaking urine during exercise, or lower back pain are signs you need a postnatal physiotherapy assessment before continuing. These are common but not something you should push through.
6. Fuel properly. Breastfeeding requires an extra 330 to 500 calories per day (CDC, ACOG). If you're exercising on top of that, make sure you're eating enough. Restricting calories while breastfeeding and exercising can affect your energy and milk supply.

Frequently Asked Questions

Will exercise reduce my milk supply?

No. The Australian Breastfeeding Association confirms that moderate and aerobic exercise has no effect on breastmilk supply, nutrients, immune factors, or mineral levels. Your supply is driven by demand - how often and how well your baby feeds. A 1994 study in the New England Journal of Medicine found that women exercising five days a week showed no change in milk volume or composition. Stay hydrated and eat enough, and your supply will be fine.

Can I use a regular sports bra as a nursing bra?

You can, but it's impractical for breastfeeding. A regular sports bra (especially compression styles) needs to be removed entirely to feed. A nursing sports bra gives you the same support with drop-down cups for easy feeding access. If you're exercising regularly while breastfeeding, a dedicated nursing sports bra is worth the investment - it replaces your sports bra and your nursing bra in one.

Is it better to go braless while breastfeeding?

Going braless is fine at home or during rest, but for exercise it's not recommended. Without support, breast tissue stretches during high-impact movement, which can cause discomfort and longer-term changes to breast shape. A well-fitted nursing bra supports your breasts during activity while still giving you easy feeding access.

How soon after a feed can I exercise?

You can exercise immediately after feeding - in fact, this is ideal. Your breasts will be at their lightest, making high-impact movement more comfortable. There's no minimum waiting time after breastfeeding before you can work out.

Do I need different bras for different activities?

If you only buy one nursing sports bra, choose a high-impact style - it works for everything from walking to running. If you exercise frequently and want options, pair a high-impact nursing sports bra for gym and running with a softer nursing sleep bra for yoga and stretching.