We all know exercise is good for us. Sometimes, however, it takes a scientific study to show us how good.

For instance, it is widely accepted that exercise is good for mothers-to-be, with no down side for the baby. Now, a new study has found that not only do women benefit from exercise during pregnancy, but so do their fetuses.

Ten women participated in the study led by Linda E. May of the Department of Anatomy, Kansas City University of Medicine and Biosciences in Kansas City, MO. Five women were classified as exercisers and five as controls. They were further grouped according to the frequency, intensity, and length of physical activity they engaged in.

The study found significantly lower heart rates in the fetuses exposed to maternal exercise. The heart rates among non-exposed fetuses were significantly higher.

According to Dr. May, "This study suggests that a mother who exercises may not only be imparting health benefits to her own heart, but to her developing baby's heart as well. As a result of this pilot study, we plan to continue the study to include more pregnant women."

Dr. May presented these findings in April, 2008 at the 121st annual meeting of the American Physiological Society, part of the Experimental Biology 2008 scientific conference.