Any person that's been pregnant knows it's a tough road that takes a toll on the body and it might be tempting just to spend the whole nine months in bed.
But if you can manage it, exercising during pregnancy might be the best way to benefit your child's health later in life.
According to a new study carried out in the US, exercise during pregnancy prevents the transmission of metabolic diseases from an obese parent to the baby.
This means that soon, a woman's first trip to the doctor after conceiving might include a prescription for an exercise programme.
Researchers at the University of Virginia School of Medicine conducted the study using lab mice and say if the findings hold true in humans, it will have "huge implications" for helping pregnant women ensure their children live the healthiest lives possible.
"Most of the chronic diseases that we talk about today are known to have a fetal origin. This is to say that the parents' poor health conditions prior to and during pregnancy have negative consequences to the child, potentially through chemical modification of the genes," said lead researcher Dr Zhen Yan.
"We were inspired by our previous mouse research implicating that regular aerobic exercise for an obese mother before and during pregnancy can protect the child from early onset of diabetes. In this study, we asked the questions: what if an obese mother exercises only during pregnancy, and what if the father is obese?"
Dr Yan says the results were "striking".
Exercise during pregnancy prevented a host of epigenetic changes which affect the workings of the offspring's genes, the researchers found. Maternal exercise, they determined, completely blocked the negative effects of either mother's or father's obesity on the offspring.
"The take-home message is that it is not too late to start to exercise if a mother finds herself pregnant. Regular exercise will not only benefit the pregnancy and labour but also the health of the baby for the long run," says Dr Yan.
"This is more exciting evidence that regular exercise is probably the most promising intervention that will help us deter the pandemic of chronic diseases in the ageing world, as it can disrupt the vicious cycle of parents-to-child transmission of diseases."