Physical activity is beneficial for pregnant women in lowering their risk of developing gestational diabetes. A study, reported in Epidemiology (January 2006), evaluated the association between gestational diabetes and "perceived exertion" in thin and overweight women. This evaluation was accomplished, in part, by interviewing the women on how they rated their energy level during usual exercise in the year prior to becoming pregnant.
The researchers learned that, the higher the level of perceived exertion, the lower the risk of gestational diabetes. The women who reported very strenuous usual exertion were 81% less likely to develop pregnancy-induced diabetes. The women who reported moderate usual exertion had a 59% lower risk.