Babies of mothers who exercised during pregnancy appear to have stronger hearts than babies of sedentary mothers. These findings were presented this week at the Experimental Biology annual meeting in Washington, DC.

“It is my hope that these findings will show that efforts focused on improving health need to start during pregnancy rather than in childhood,” says lead author, Linda E. May.

“Most of the focus today is on school-age children, but interventions should be focused long before that.”

In a previous study, May and her colleagues found that pregnant women who exercised at least 30 minutes three times a week had fetuses with lower heart rates — a sign of heart health — during the final weeks of development.

Now the team has revealed that the fetuses’ improved cardiovascular heart control is maintained one month after pregnancy, which indicates that mothers’ efforts to stay active have lasting effects.

The study, which comprised 61 moms-to-be, monitored maternal-fetal and infant heart function. The women’s aerobic activity levels ranged from power walking to running. Some of the more active participants also lifted weights and practiced yoga.

“The system that controls heart function is known to improve with regular aerobic exercise,” May explains. “And improved heart control function is evidence of a healthy cardiovascular system and overall health. Not only did the mothers’ exercise help maintain and improve their own health, but it set their babies up for a healthier start.”

Experimental Biology – April 12, 2011.