Can exercise have an effect on breastmilk and milk supply?
Many mums wonder if exercise can affect their breastmilk and milk supply. Anita Guerra, Midwife and Fitness Trainer, answers the most common questions around breastfeeding and safe return to exercise.
Safe return to exercise is critical after having a baby, specifically in the first 12 months, both for mum’s sanity and so she can meet the demands of her baby and her family.
In the first 6 -8 weeks post-birth, dependent on the type of birth you had, walking is great exercise to start with. Just 20 minutes once or twice a day will help improve your circulation, reduce fluid retention, reduce isolation and increase your mood and energy. And, it’s important to get you active again. If you don’t enjoy walking on your own, make time with your partner, walk with a mothers’ group or catch up with friends.
Research shows that exercise assists in the wellbeing of new mums in many ways. For example, exercise can:
- improve heart health and general fitness;
- improve mental wellbeing and energy levels;
- reduce stress levels;
- assist with weight control;
- improve bone strength;
- assist with the treatment of post-natal depression.
Furthermore, the benefits of exercise include:
- higher level of cardiovascular fitness;
- improved blood lipid profiles and insulin response
- a feeling of well-being from improved energy and reduced stress levels
- enhanced maternal-infant relationship
- alleviation of depression symptoms in those with major depressive disorders.
Can exercise have an effect on breastmilk and milk supply?
However, breastfeeding mothers may worry whether exercise can affect their breastmilk and milk supply. This is a common question I receive as a Midwife.
Research has shown that moderate exercise does not affect milk supply, milk composition or baby’s growth.
Some research has looked at the level of lactic acid (a by-product of high intensity exercise) in mothers’ breastmilk after exercise. While lactic acid can increase in breastmilk following maximal exercise (exercising to the extreme of exercise intensity), mild or moderate exercise does not cause lactic acid to increase in breastmilk and does not affect a baby taking the milk. Exercising to exhaustion may have a short-term effect on lactic acid and IgA content of a mother’s milk.
Most mothers tend to exercise to a moderate intensity to lose weight, and improve/maintain fitness and overall wellbeing. Regardless, there is no evidence to suggest that breastmilk with increased lactic acid levels harms a baby in any way.
Moderate exercise therefore does not affect:
• breastmilk supply
• important immune factors in breastmilk (SIgA, lactoferrin, and lysozyme)
• major minerals in breastmilk (calcium, phosphorous, magnesium, potassium and sodium)
• major nutrients in breastmilk (fat, protein, lactose) or energy density.
As a Midwife, I encourage my girls to breastfeed their baby prior to exercise so their breasts are more comfortable during their fitness class, there is a less chance of lactic build up and their baby is more settled which allows mum to be more focused on her training.
Does exercise affect the growth of your baby?
Recent research suggests that mothers can exercise and breastfeed without affecting the growth of their babies. Research also suggests that, once breastfeeding is established, overweight women may do moderate exercise 4 days per week to promote a weight loss of 0·5 kg per week without affecting their baby’s growth.
On a personal note, I exercised and breastfed both my babies with no issues with supply. I do advise mums not to over-exert themselves while breastfeeding, and to make sure they follow a wholefood diet and drink water to keep their supply up and to maintain energy stores. And, to rest more when needed to replenish supply.
Let’s talk breastfeeding, exercise and ‘loose ligaments’
A woman’s amazing body is designed to carry a baby through pregnancy to motherhood and should be able to breastfeed – if there are no implications not to, like PCOS.
During pregnancy and childbirth, the hormone relaxin allows our pelvic ligaments to loosen so we can have a baby vaginally if possible. After you give birth, the relaxin generally hangs around for around 12 weeks postpartum, but generally longer if you are breastfeeding. This is why I advise women to ensure they are in a Safe Return to Exercise Group post-birth for at least the first 12 months to ensure safe recovery.
If you had any complications during pregnancy like pelvic girdle pain, back pain, SPD, pelvic floor issues 0r incontinence (just to name a few), it’s still important to monitor these postpartum as some of these conditions can prolong after birth. They will require further attention with the right trainer and a Women’s Health Physio to put a plan in place on how to return to exercise safely.
There is no evidence to suggest that breastfeeding plays a role in causing, maintaining or worsening any of these conditions. Provided mum is comfortable, breastfeeding is not a reason why she has to avoid any form of exercise.
Here are a few exercise tips for breastfeeding mums:
• Breastfeed prior to exercising for your comfort.
• Wear a supportive bra.
• Drink water.
• Eat nutritious wholefoods for energy and your milk supply.
• Rest as needed to help boost supply.
• Keep stress to a minimum.
• Exercise 3-4 days a week in a safe environment.
• Find a safe trainer at www.bodybeyondbaby.com.au.
Anita Guerra is a Registered Midwife and Certified Fitness Trainer. She runs Fit For 2 in South Morang, Victoria. To find out more about her and get in touch, click here.
You can also find her on Instagram.
Partial Information provided from Renee Kam, Physiotherapist, IBCLC and ABA Breastfeeding Counsellor. (Australian Breastfeeding Association)
1. Amorim AR, Linne YM, Lourenco PMC 2008, Diet or exercise or both for weight reduction in women after childbirth. Cochrane Database Systematic Reviews, Issue 3.
2. Lovelady C 2011, Balancing exercise and food intake with lactation to promote post-partum weight loss (Review). Proc Nutr Soc 70(2):181–4.
3. Rich M, Currie J, McMahon C 2004, Physical exercise and the lactating woman: a qualitative pilot study of mothers’ perceptions and experiences. Breastfeed Rev 12(2):11–7.
4. Lovelady CA, Bopp MJ, Colleran HL, Mackie HK, Wideman L 2009, Effect of exercise training on loss of bone mineral density during lactation. Med Sci Sports Exerc 41(10):1902–7.
5. Daley A, Jolly K, MacArthur C 2009, The effectiveness of exercise in the management of post-natal depression: systematic review and meta-analysis. Fam Pract 26(2):154–62.
6. Norman E, Sherburn M, Osborne RH, Galea MP 2010, An exercise and education program improves well-being of new mothers: a randomized controlled trial. Phys Ther 90(3):348–55.
7. Carey GB, Quinn TJ 2001, Exercise and lactation: are they compatible? Can J Appl Phys 26(1): 55–74.
8. Wright KS, Quinn TJ, Carey GB 2002, Infant acceptance of breast milk after maternal exercise. Pediatrics 109(4): 585–589.
9. Dewy K, Lovelady C, Nommsen–Rivers L, McCrory M, Lonnerdal B 1994, A randomised study of the effects of aerobic exercise by lactating women on breast-milk volume and composition. New Engl J Med 330: 449–453.
10. Lovelady CA, Hunter CP, Geigerman C 2003, Effect of Exercise on Immunologic Factors in Breast Milk. Pediatrics 111(2):e148-e152.
11. Fly AD, Uhlin KL, Wallace JP 1998, Major mineral concentrations in human milk do not change after maximal exercise testing. Am J Clin Nutr 68(2):345–9.
12. Daley AJ, Thomas A, Cooper H, Fitzpatrick H, McDonald C, Moore H, Rooney R, Deeks JJ 2012, Maternal Exercise and Growth in Breastfed Infants: A Meta-analysis of Randomized Controlled Trials. Pediatrics 130(1): 108–114.