Exercise and Breast Milk
Exercise does not make your breast milk 'sour' or harmful to your baby — this is a persistent myth. While intense exercise does temporarily increase lactic acid in breast milk, studies show babies accept the milk just fine. Moderate exercise has no effect on milk volume, composition, or your baby's growth. Stay active — it's great for your physical and mental health postpartum.
Myth: "You need to pump and dump after working out because lactic acid makes your milk sour." False. Multiple studies have shown that babies nurse normally after maternal exercise. Lactic acid levels return to baseline within an hour, and even at peak levels, babies don't refuse the milk.
Always confirm with your doctor or lactation consultant before making dietary changes while breastfeeding.