Excessive weight gain during pregnancy increases the risk of suffering illnesses such as hypertension and gestational diabetes, or of having a premature birth or a birth by Caesarean; furthermore, it also has negative effects on the newly-born and increases the risk of infants being overweight by 30%.

Aware of the importance of preventing gestational weight gain, both in mother and child, researchers from the University of Granada, Madrid Polytechnic University and the European University carried out a study on the benefits of exercising during pregnancy to prevent weight gain, entitled "Supervised Exercise - Based Intervention to Prevent Excessive Gestational Weight Gain: A Randomized Controlled Trial", which has been published in the journal >em>Mayo Clinic Proceedings.

The research, which took place between 2007 and 2011, and in which 962 pregnant women took part, reveals that, in healthy women, moderate-intensity supervised exercise, begun immediately following the first prenatal consultation, avoids excessive weight gain on ending this period and reduces the risk of suffering from associated illnesses, such as gestational diabetes or hypertension.

Furthermore, the study shows that the benefits of exercise are greater in women of normal weight than in those that are overweight or obese, who can also benefit from exercise, but to a lesser extent.

Dr. Rubén Barakat, head researcher of the study and lecturer at the Madrid Polytechnic University, declares that "thanks to the joint work of professionals from the fields of Sports Science and Medicine, we have been able to demonstrate the importance of correct exercising habits, supervised and directed during the pregnancy. In this sense, there is still a lot to do, since we believe that the benefits of programmed physical excercise during pregnancy can even affect the infant's first years of life. Recent scientific evidence allows us to consider this idea. For this, new studies are needed to research the influence of gestational exercise on maternal, fetal and child parameters; it would be a great mistake not to extend this type of research, using more extensive and ambitious clinical tests. This is only the tip of the iceberg".

In turn, Dr. Jonatan Ruiz, main author of the article and a Ramón y Cajal researcher at the Faculty of Sports Science of the University of Granada, underlines that "the benefits of regular physical activity during pregnancy and the post-natal period are the same well-known benefits that the general population obtain. Pregancy is an ideal time to change habits and to adopt a physically-active lifestyle during this period and for the rest of life".

The researcher and professor of Exercise Pysiology at the European University,Alejandro Lucía, adds that "in general, the benefits of physical exercise are greatly neglected in current medicine and this type of studies helps to create more knowledge so that doctors will prescribe exercise that is personalized and in accordance with the conditions of each sector of the population".

Lower weight gain

To carry out this study, the women were randomly divided into two equal groups. The first group, as well as carrying out the usual pregnancy healthcare instructions, took light-to-moderate aerobic exercise 3 times a week in sessions of 50-55 minutes, from weeks 9 to 39 of the pregnancy. The second group followed the usual recommendations for any pregnant woman.

The results of the study show that weight gain in the women who followed the exercise programme was less that in the women that did not; more specifically, the risk of gaining weight in excess of the recommendations of the American Institute of Medicine was 40% lower in the women who followed the regime of physical activity. To analyse the results, the researchers took into account data such as age of the mother, gestational age, studies and weight before pregnancy.

Likewise, even though that, in the case of the obese or overweight women, taking exercise 3 times a week has not been as efficient, there has been an 86% reduction in the risk of having a baby with macrosomia (inordinate weight of over 4 Kg in newly born).

The researchers state that, through this type of studies, "we wish to emphasize the importance of maintaining the health of pregnant women, as well as their children, by reaching an optimum weight; hence the importance of taking physical exercise".