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Breastmilk exercise
First Years Pregnancy Jun 30, 2020
4 Minutes

How exercise (pre and postnatal) actually changes your breastmilk!

We all know that exercise is beneficial for our health. However, new research shows that even simply walking/increasing steps during pregnancy and lactation can be crucial for your baby’s future health. This is because the latest research has found it actually changes key components in your breastmilk. This in turn can have an influence on your baby’s genetics and lifelong health. Pretty cool stuff! Here is what you need to know… 

Increasing your daily steps actually changes your breastmilk composition:

The prestigious journal Nature published a study showing that activity (which it can be as little as increasing your daily step count) changes breastmilk composition. Specifically increasing an important Oligosaccharide which has shown powerful impact protecting long term heart and metabolic health. (1) Two issues which have become significant issues in our modern society.

We know that exercise is good during pregnancy but here is an extra clue as to why…. 

Breastmilk is a pretty remarkable thing. It contains a whole host of extremely beneficial elements for a growing baby. Specifically prebiotic elements known as Oligosaccharides. They make up around 5-15% of human (and mouse) milk. That is vs. just 0.5% in cows milk. There are also around 150 different types in human milk (vs 40 in cows). These prebiotic components are super important for a baby’s health.

This is how breastmilk feeds/shapes a baby’s all important gut microbiome. Setting the stage for future health: 

Prebiotics feed the bacteria we have in our gut. Recent science is telling us that having a diverse and balanced mixed is crucial for long term health. Particularly in the earliest days when the foundations are laid. Click here for MUCH more! 

Unlocking exercise’s powerful impact on breastmilk: impacting a baby’s genetics! 

This new research (1) shows that exercise pre and during pregnancy boosts a crucial oligosaccharide known as 3-sialyllactose (3-SL). It appears this actually has an epigenetic impact. What does that mean? It means it influences which genes are ‘turned on and off’ in the body. Specifically the researchers showed that it had a positive impact on cardio, glucose metabolism and levels of fatty tissue over the longer term. Interestingly, it was more pronounced in male offspring than female.

The research demonstrated that:

’maternal high fat diet decreased 3-SL, whereas maternal exercise increased 3-SL in milk regardless of diet’ (1)

Not everyone is able to ‘exercise’ but here is the good news:  

Of course if your pregnancy is going along smoothly and your doctor has said that it is ok to exercise then great. There are a whole host of benefits including this one. Click here for what you should know about exercise during pregnancy. 

However, the good news is that ‘exercise’ is a loose definition. In this research it has been shown that simply increasing movement and activity can have a benefit. This was regardless of your BMI. So, even just getting out and about and walking more can be really helpful when you can. Marathon running not necessary!

But, can exercise impact your breastmilk supply?! 

As with anything, safety comes first. Always speak to your doctor about exercising during pregnancy and about your recovery after. Your doctor will give you the nod when it is ok to start getting active again after you’ve had your baby. Staying away from the extremes is the key. Not sedentary and not too intense. However, during pregnancy and the postnatal period the early days getting out for a walk is good for mind, body and soul.

Extreme exercise can impact breastmilk supply. However, proper nutrition and moderate exercise is beneficial when you’re ready. Click here for all you need to know from our resident expert pre and post natal trainer Natalie Ferris. Particularly when it comes to ensuring exercise does not impact milk supply. 

Getting enough of the good stuff: 

One of the most common issues people have is with supply. The number one element is ensuring you are emptying the breast as much as possible. Doing that will trigger the body to make more. Outside of this, we have the latest science on how you can maximise your supply. Click here. 

Finally…. the ‘how to’: 

If you do have the go ahead to exercise from your doctor, knowing what you ‘can’ and ‘cannot’ do is often a big question during pregnancy. We have the ‘how to’ from our pre and postnatal trainer Natalie to help guide you through.

Click here for the ‘how to’ and what to consider for exercise during pregnancy. 

Click here for the ‘how to’ and what to consider for exercise postnatal. 

However. Once again, ‘exercise’ can be as simple as moving and taking a walk. It’s all about finding what works for you. The more you enjoy it, the more likely you’ll keep doing it. Have fun!


Harris JE, Pinckard KM, Madaris K, Sims C, Goodyear LJ, Stanford KI: Exercise-induced 3′- sialyllactose in breastmilk is a critical mediator to improve metabolic health and cardiac function in mouse offspring: Nature Metabolism: June 2020. 


This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The information on this website has been developed following years of personal research and from referenced and sourced medical research. Before making any changes we strongly recommend you consult a healthcare professional before you begin.

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