Breastfeeding and Exercise

Today’s Motherhood Monday post was inspired by an email from an online client regarding breastfeeding and exercise.


She was interested in joining the Run Club but was told by her local Pilates instructor that she should avoid high-impact exercises while breastfeeding.

I hadn’t heard this recommendation before so I thought it was a good time to double check the research, consult with my colleagues and clarify some of the concerns surrounding breastfeeding and exercise.


There are a few things to consider if you embark on an exercise program while breastfeeding:

1. Relaxin

While pregnant your body produces a hormone called Relaxin which allows your joints to loosen and stretch to accommodate the growing baby. This hormone is still present postpartum, especially during the first 6 weeks. Therefore, it’s important to be aware that your body may feel different and you may be at a slight increased risk for injury. I am not aware of any studies that show evidence that exercise/running leads to joint damage. In my opinion, this is something to pay attention to but not necessarily a reason to avoid exercise. It does, however, make it all the more important to incorporate strength training into your routine to support your joints, spine and posture (Pilates would be great for this).

2. Lactic Acid in Breast Milk

There have been some studies that show that lactic acid is present in breast milk following exercise which can lead to a sour tasting milk. According to the latest research on breast milk and lactic acid, this is only an issue when mothers are exercising to the point of exhaustion, meaning 100% intensity. Lactic acid can be present in breast milk for up to 90 minutes post workout. There are no known harmful affects for baby. If your baby seems unhappy while nursing after you exercise this could be something to consider. Another thing to consider would be showering first to wash the salt/sweat off your skin before feeding.

3. Breast Milk Supply

There have not been any studies that show that exercise impacts milk supply. In fact, according to KellyMom.Com one study even showed that exercise increased milk supply. Regardless, it is imperative to stay hydrated and keep you calorie count up if you are choosing to exercise and breastfeed. Breastfeeding mothers need an extra 500 calories per day without exercise, so adjust your meals/snacks accordingly.



–  The most important time to use caution while exercising during the postpartum period is during the initial 6-8 weeks.

– Always check with your doctor before resuming or beginning an exercise program.

– Drink plenty of water to stay hydrated for your workouts and to maintain milk supply.

– Increase your daily caloric intake to  maintain milk supply.

– Listen to your body and be gentle with yourself. It will take time to return to your previous level of fitness. Pay attention to the way your new body feels and don’t overdo it.

– Feed your baby prior to exercise to alleviate full breasts and to reduce the amount of lactic acid build up in your  milk.

– Wear a comfortable, supportive sports bra especially during high impact exercise.

In my opinion, the benefits of exercise far outweigh the concerns. Reduced stress, improved circulation, increased confidence, higher immunity levels and alleviation of depression symptoms are just a few of the benefits that will improve your quality of life and help you be a better mother for your little one.

Questions? Post them below!


sources: KellyMom, ACOG.

Disclaimer: please remember, this blog is for educational purposes and should never be used to replace the role of your health care provider. Always consult with your doctor before beginning an exercise routine.


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