Exercise and breastfeeding

After having a baby, movement can take many forms. For some mums, it’s gentle walks with the pram, stretching on the lounge-room floor, or following a short Pilates or yoga video while the baby naps. It can be hard to find time or energy for anything more and that’s okay. 

These small amounts of movement can make a difference, reducing stress and supporting your emotional wellbeing.

As time goes on, you might start thinking about returning to (or taking up) more strenuous activities – running, strength training, swimming or aqua classes, group fitness or at home workouts that get your heart rate up.

Exercise can help you feel stronger, calmer and more confident as you adjust to life with a new baby. Studies show that physical activity can:

• improve your heart health 
• boost mood and increase energy
• reduce stress
• support healthy weight changes after birth  
• help maintain bone strength
• form part of treatment for post-natal depression

These benefits are seen with a wide range of movement and exercise levels.^1_3

At the same time, many mums have questions about whether exercise affects breastfeeding in any way. 

Moderate and aerobic exercise has no effect on:

• your breastmilk supply
• the nutrients in your milk such as fat, protein or lactose
• immune factors like SIgA, lactoferrin or lysozyme
• mineral levels including calcium, magnesium or potassium
• the temperature of your milk. 

Your milk remains the same quality and quantity after exercise.^1_2

Some mums are concerned about lactic acid build up after exercise and whether this affects their breastmilk. Mild or moderate exercise doesn’t cause lactic acid to increase in breastmilk and won’t affect your baby taking the milk. 

Intense (maximal) exercise can cause a temporary rise in lactic acid. Sometimes this can change the taste of the milk but babies will usually still accept it. There is no evidence to suggest that breastmilk with increased lactic acid levels will harm your baby in any way.⁴

Exercise doesn’t affect your baby’s growth. Babies continue to grow normally when their mum is breastfeeding and physically active after birth.^1_2

If you’re aiming to lose weight, gentle and moderate activity, combined with small, steady changes, won’t affect your baby’s development.²

Your body is designed to carry a baby through pregnancy, give birth and breastfeed. Hormones help the ligaments in your pelvis loosen so your baby can be born. After birth, these hormone levels drop, but your muscles, joints and posture may still feel different for a while. The type of birth you had may also impact the time it takes to recover. 

Some mums notice pain in their pelvis or lower back, loose-feeling joints, or leaking when they move. These changes can affect how comfortable exercise feels and can take time to settle. 

Breastfeeding doesn’t make pelvic floor problems or 'loose ligaments' worse. It’s safe to keep moving and to exercise at a level that feels right for you.⁵

A women’s health physiotherapist can help if you’re experiencing any pain or leaking. They can check what’s happening and suggest ways to move that feel more comfortable for you.

Life with a baby often means that the way you used to exercise, or the time of day you did it, no longer fits. Many mums find that being flexible with timing helps make activity more achievable.

• Work with feeds or naps, exercising when your baby is more settled.
• Choose activities your baby can come along to, like walking with baby in a carrier or running with a pram.
• Think small and flexible, using short windows rather than planning long sessions.
• Use support when it’s available, even brief help from someone else can make movement easier.
• Let routines change, as the time or type of exercise that worked before may not fit right now.

When you feel ready, you can return to (or take up) more strenuous exercise. This might include activities that raise your heart rate, make you breathe harder, or challenge your strength. Try to build up gradually, listening to your body and increasing intensity over time.

Exercise at higher intensities is still compatible with breastfeeding. Milk supply, nutrients and immune factors stay the same, and babies continue to feed as usual.^1_2

You can return to harder exercise at your own pace. If something doesn’t feel comfortable, you can slow down, reduce the intensity or try a different type of movement. 

• Wear a supportive, well fitted bra.
• Comfortable clothing: Choose clothing that doesn’t press on your breast tissue
• Breastfeed or express before exercise, as full breasts may feel uncomfortable during movement.
• Managing around frequent feeding: If your baby often cluster feeds at a certain time of day, it can help to choose a different time for your workout so you’re not stressed by back to back feeding and exercise.
• Plan ahead for longer sessions: If you’ll be active for longer than usual,
• Staying hydrated is important: Drink water before, during and after exercise.
• Heat: If exercising in hot weather, be mindful of heat stress, for both you and your baby if they’re coming along
• Food: Make sure you’re eating enough to support both breastfeeding and increased activity.
• Plan feeds or pumping so you’re not going too long between milk removals.
• Leaking: If you’re prone to leaking with vigorous exercise, breast pads may help you feel more comfortable.

Start slowly and build up your intensity over time. There is no need to avoid any particular form of exercise while breastfeeding if it feels comfortable for your body.

If you’re playing a team sport, it can help to think ahead about how your baby and feeding will fit around training or game time. Many mums in community sport find simple arrangements make the whole activity run smoothly.

• Bring your baby along with support. Settle your baby on the sideline in a pram or carrier, with a partner, friend or another parent watching them during play. This means you can step in quickly if your baby needs you. Make sure they’re in a safe place away from equipment, balls, or fast moving players.
• Feed before you start. It’s more comfortable to breastfeed or express just before warm up to avoid breast fullness during the game.
• Use game breaks when needed. Community teams are usually flexible. Some mums feed during half time or are briefly subbed off to settle or feed their baby, then return to play when ready.
• Lean on your team. The key is clear communication. Once teammates know you may need a short break to feed your baby, they’re usually very understanding and supportive.

You might find it helpful to speak with:

• a women’s health physiotherapist for pelvic floor symptoms or guidance returning to exercise
• an ABA breastfeeding counsellor if you have questions about supply, feeding timing, or just need reassurance