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Your baby is NOT sucking the calcium out of your bones.

That's the line all over social. What's actually happening is your body mobilizing a small amount of calcium from bone to help make milk. And across 14 studies, it looks a lot more like a temporary loan than a permanent loss.

This week I sat down with two first-time podcasters from Duke.

Dr. Emma Kosbab started this systematic review and meta-analysis as a PT student. Dr. Laura Pietrosimone was her research mentor. Together with their team they screened 6,568 citations to land on 14 studies about breastfeeding and bone density, and we get into what that means for the mom who wants to run and lift. 🔹 Why breastfeeding touches bone at all (and why "mobilizing" is a much less scary word)

🔹 What happens at the low back, the hip, and the whole body, from early postpartum through weaning

🔹 Whether breastfeeding longer changes the picture

🔹 Who may want to pay closer attention, like moms with a history of bone stress injury or under-fueling

🔹 Who belongs on your care team if that's you

🔹 The questions nobody has answered yet, starting with how many extra calories breastfeeding actually takes If you're nursing and wondering whether your bones can handle getting back to running or lifting, this one's for you.

Read the paper:

Kosbab E, Christopher S, Horn ME, et al. Changes in Bone Mineral Density in Postpartum People During Lactation: A Systematic Review and Meta-Analysis. J Athl Train. 2025. https://doi.org/10.4085/1062-6050-0497.25

About Emma: Emma Kosbab, PT, DPT, LAT, ATC is an outpatient ortho and sports PT and outreach athletic trainer with Duke Health, and a contract PT/AT with USA Paralympic Swim. She loves working with female athletes and moms through pregnancy and postpartum. Off the clock: volleyball, running, lifting, and anything outside (Utah roots). Connect with Emma: Instagram @em_kosbab12 · https://www.linkedin.com/in/emma-kosbab/

About Laura: Dr. Laura Pietrosimone, PT, DPT, PhD is an Assistant Professor and clinical researcher in Duke's Doctor of Physical Therapy Division. She studies how movement and physical activity change after lower extremity injury, and she's passionate about female athlete health across the lifespan. She's a mom of three, a runner, and happiest in the mountains. Connect with Laura: Instagram @lstanpietro · https://www.linkedin.com/in/laura-stanley-pietrosimone-4ba30615/

This episode is education, not individualized medical advice.

The Active Mom Podcast — a real mom's guide to pregnancy, postpartum, perimenopause & beyond, for active moms and the professionals who help them get there.

Quick-hit conversations with moms, providers, and researchers... because you don't have a lot of free time (you're probably listening at 1.5x right now).

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