Breastfeeding and Exercise
You might be wondering if it’s safe to get back into exercise while you’re breastfeeding. Or you’ve already started moving again and noticed things feel different this time, maybe some new aches, some dryness, some fatigue that wasn’t there before.
There’s a reason for all of it.
Exercise is safe, and it helps
Exercise during breastfeeding is safe and encouraged. It doesn’t affect your milk supply or your baby, so you don’t need to hold back out of worry on that front. It can genuinely support your recovery, rather than working against it.
You’re also carrying physical load you might not have expected. Feeding for long stretches, often hunched forward and looking down, puts real strain through your shoulders and upper back. Many women don’t realise how much this adds up over a day of feeding.
This is where exercise can genuinely help. Strengthening your upper back and shoulders can ease that built up tension, and support better posture as you move through your day with your baby.
Getting comfortable first
You’ve probably found a breastfeeding bra you love for everyday feeding, but it’s not always the right choice for exercise. A proper supportive sports bra will make a real difference, and breast pads are worth having on hand for any leakage during your session.
It’s also worth feeding or expressing before you exercise, so your breasts aren’t full and heavy while you move. That’s purely about your own comfort. It has nothing to do with the milk itself, which brings us to something worth clearing up. Exercise doesn’t affect your milk. Moderate exercise doesn’t raise lactic acid enough to change its taste or its makeup, and even after a really hard session, most babies still take it normally. So however you choose to manage feeds around exercise, it’s a comfort decision, not a safety one.
One more thing worth knowing if you’re heading to a postnatal class without your baby. Hearing another baby cry in the room can trigger your letdown, and a leak in the middle of class is completely normal. Having pads on and knowing this might happen takes the pressure off if it does.
Staying hydrated
Breastfeeding takes up more of your fluids and calories than you might expect. Your body is working hard to make milk, on top of everything else it’s recovering from.
Keep water close by, especially during feeds and during exercise. It’s easy to under drink, so make it part of your routine rather than something you remember to do later.
This isn’t about restricting anything. Your body needs more right now, not less, so eating and drinking enough supports both your milk supply and your own energy through exercise and recovery.
For the specific numbers on how much more fluid and energy you need while breastfeeding, see our article on fluid intake and hydration.
Ligaments, tendons and joints need time
Your body keeps oestrogen low on purpose while you’re breastfeeding. It’s part of how your body makes milk. Along with that comes an effect on your tendons and ligaments, since oestrogen normally helps keep them strong.
You might notice you feel less stable or more prone to niggles than before, especially around your hips, pelvis and lower back. This is a normal part of what your body is doing right now, not something going wrong.
It also affects your bones. Breastfeeding causes a temporary drop in bone density, mainly in your lower spine, and this is expected. It recovers after weaning or within about 18 months. Exercise that combines resistance training with weight bearing movement has been shown to help protect your spine during this time.
Give yourself the same patience here that you would with any other part of your recovery. Build back up gradually, and trust that your body is doing exactly what it needs to do.
Vaginal dryness
The same low oestrogen that’s helping your body make milk can also mean vaginal dryness. It’s common, and it catches a lot of women off guard because no one mentioned it might happen.
It can affect comfort during exercise, especially anything higher impact.
A good lubricant can help day to day. If higher impact movement feels uncomfortable right now, lower impact options are a completely reasonable choice while your body is in this phase. It’s also worth talking to your GP, since vaginal oestrogen can be a good option for some women.
This tends to ease as your hormone levels shift again once breastfeeding reduces or stops.
References
Chidi-Ogbolu, N., & Baar, K. (2019). Effect of Oestrogen on Musculoskeletal Performance and Injury Risk. Frontiers in Physiology, 9, 1834. https://doi.org/10.3389/fphys.2018.01834
Holmen, M., Giskeødegård, G. F., & Moholdt, T. (2023). High-intensity exercise increases breast milk adiponectin concentrations: a randomised cross-over study. Frontiers in Nutrition, 10. https://doi.org/10.3389/fnut.2023.1275508
Jones, P. A. T., Moolyk, A., Ruchat, S. M., Ali, M. U., Fleming, K., Meyer, S., Sjwed, T. N., Wowdzia, J. B., Maier, L., Mottola, M., Sivak, A., & Davenport, M. H. (2025). Impact of postpartum physical activity on cardiometabolic health, breastfeeding, injury and infant growth and development: A systematic review and meta-analysis. British Journal of Sports Medicine, 59(8), 539-549. https://doi.org/10.1136/bjsports-2024-108483
Kosbab, E., Christopher, S. M., Horn, M. E., Tally, Z., Adams, V., Ledbetter, L., Hendren, S., & Pietrosimone, L. S. (2025). Changes in Bone Mineral Density in Postpartum People During Lactation: A Systematic Review and Meta-Analysis. Journal of Athletic Training. https://doi.org/10.4085/1062-6050-0497.25
Oboh, I., Coleman, C. & Cremona, A. (2021). The influence of lactation and its duration on bone mineral density in pregnancy and postpartum: A systematic review with meta-analysis. Clinical Nutrition ESPEN, 46, 121–132.5
World Health Organization. (2025). Infant and young child feeding: Model chapter for textbooks for medical students and allied health professionals (2nd ed.). Geneva: WHO. https://iris.who.int/server/api/core/bitstreams/2966cbcb-d5a0-4ee5-b39f-4dc1bde543ba/content
Zhou, Z., Wei, X., Zhang, X., Ainsworth, B. E., Lü, J., & Liu, Y. (2026). Effects of different types of exercise over 24 weeks on bone mineral density in postmenopausal women: A systematic review with pairwise and network meta-analysis of randomized controlled trials. Journal of Sport and Health Science, 15. https://doi.org/10.1016/j.jshs.2026.101127
Developed by the WHEN Clinical Team
Clinically reviewed by the WHEN Clinical Governance Committee
Last reviewed: 30/07/2026
With clinical input from Peta Titter, RN, Grad Cert Continence Nursing, Advanced Diploma of Pilates. Honours by Research (diastasis recti). PhD candidate, University of Tasmania. Founder and CEO, WHEN.
