Pregnant women who exercise more each week tend to have babies with higher birthweights, even when you account for how long the pregnancy lasted. It’s not just about going longer—it seems like exercise itself might help the baby grow bigger.

If pregnant women who are at moderate risk for high blood pressure do more physical activity each week, their babies tend to be born later and weigh more at birth, which might help the baby grow healthier without becoming too big.

If a pregnant woman who might develop high blood pressure exercises at a moderate pace, it won't make her baby smaller — so it's safe for the baby's growth.

Pregnant women who exercise more during pregnancy—like walking or swimming a lot—tend to have lower blood pressure in the last few months of pregnancy, which might help keep their hearts healthier.

If pregnant women at moderate risk for high blood pressure do regular, supervised workouts like walking, lifting light weights, or a mix of both, three times a week, it won’t make them more likely to have their baby too early.

If a pregnant woman gets at least 150 minutes of moderate exercise each week, she’s less likely to develop gestational diabetes, high blood pressure during pregnancy, or pre-eclampsia.