There is a large study from Norway about the connection between the birth weight of a baby and the exercise done by the mother during pregnancy.

A study conducted at the Norwegian Institute of Public Health in Oslo found that exercising during pregnancy has only a very minor impact on the baby’s birth weight, though the exercise is good for both mother and child.

However, the study found that those women who were heavier before getting pregnant were more likely to have heavier children.exercise during pregnancy

It was found that each unit of increase in the pre pregnancy weight (BMI) of the woman was likely to cause a 20 gram increase in the baby’s birth weight. So, if BMI of a woman went up from 24 to 29, it would likely cause about a 103 gram increase in the baby’s birth weight.

In the study, pregnant women did brisk walking, bicycling, jogging, fitness or weight training and aerobics, however all of this activity during the pregnancy had no impact on the baby’s weight.

“Exercise during pregnancy cannot be used as a means of ‘normalizing’ birth weight,” according to Caroline Fleten and her team who carried out the study. The focus has to be on normalizing weight of a woman prior to her getting pregnant in order to prevent overweight babies.