Healthcare workers and public health professionals struggle every day to find ways to quell the growing obesity epidemic. There is new evidence from rodent studies that an expectant mother could give her child a leg up to lifelong health simply by staying active during her pregnancy.
Scientists at Joslin recently published a study explaining the link between an offspring’s metabolism and how much its mother exercised during her pregnancy. Though the study looked at mice, the lead author Laurie Goodyear, Ph.D, head of the Section on Integrative Physiology and Metabolism at Joslin and Associate Professor of Medicine at Harvard Medical School, says that if the works translates into humans the implications for human health are enormous.
Dr. Goodyear was interested in how pregnancy, a relatively short time span, influenced offspring over the course of their adult lives. In the study, some mice had mothers who exercised prior to getting pregnant, others had mothers who exercised during pregnancy, and some had mothers who exercised both before and during their pregnancy.
Dr. Goodyear’s lab followed the offspring mice for a year (about half their life), carefully monitoring their metabolism. None of the offspring exercised; both those from active moms and sedentary moms were treated exactly the same. Regardless of their activity, researchers found that mice whose mothers exercised both before and during pregnancy were significantly healthier, right down to the cellular level.
During the experiment, the researchers didn’t force the mother mice to run or train them in any way; they simply put a wheel in their cages and let them exercise at will.
“It was very interesting because as the pregnancy progressed the mothers continued to do exercise, although it was less than a female who was not pregnant,” says Dr. Goodyear. “But this amount of exercise still had profound effects on the health of the offspring.”
In addition to looking at exercise outcomes, Dr. Goodyear was also curious about the effects of a pregnant mouse’s diet combined with its exercise habits. Previous studies have shown that if mothers ate a high fat diet during pregnancy, the offspring end up being less healthy. These offspring were heavier, with more fat cells and higher glucose levels.
Dr. Goodyear added exercise to the equation. She found that if mothers ate a high fat diet and stayed active during pregnancy then all those negative effects were erased. “The offspring, were completely normal,” says Dr. Goodyear. “They didn’t show any of the effects of the high fat diet.”
Though these studies focus on mice, Dr. Goodyear thinks there’s a good chance human metabolism works in a similar way. She points out clinical studies that show when human mothers are obese there are increased rates of obesity in their children— not only when they are kids, but into adulthood. “It’s not just a matter of the children having different feeding behaviors,” she says. “They’re predisposed to become obese metabolically from changes in their tissues.”
Dr. Goodyear is quick to point out that she’s a scientist and not a physician, so she can’t recommend the right amount of exercise for pregnant mothers. “That’s up to a woman’s obstetrician once the research is done,” she says. She does, however, think that it’s vital for expectant moms to stay active during their pregnancies and do some sort of aerobic exercise.
“Exercise has an incredible impact,” says Dr. Goodyear. “If this is a way to stop the increase in obesity and diabetes that would be an important advance in preventing these diseases.”
Recommendations from Joslin Exercise Physiologists
If you have a little one on the way, ask your doctor about low stress activities like swimming, yoga or power walking, recommends Jacqueline Shahar, M.Ed., R.C.E.P., C.D.E., manager of the exercise physiology department at Joslin. You should know about any risk factors you have like high blood pressure, and be aware of signs you are pushing it too hard like dizziness, trouble breathing, or heart palpitations.
If you don’t regularly exercise but want to start during your pregnancy, don’t try to run a marathon your first day! Ease into a routine and gradually pick up the pace and distance every week.
Walking is the easiest way to stay fit since you don’t need a gym or special equipment—just a good pair of shoes. If you’re just starting, begin with a moderately brisk pace for a mile, 3 days a week. Add a couple of minutes every week, pick up your walking speed a bit, and eventually add hills to your route. Whether you’re a pro or a novice, go slowly for the first 5 minutes to warm up and use the last 5 minutes to cool down. If you have difficulty walking, consider non weight bearing exercises such as stationary (upright or recumbent bike), swimming, or water exercises.
No matter what kind of exercise you choose to do during your pregnancy, if you stay active you will be improving not only your health but the health of your child.
Want to kick start your new routine? Start with the videos above (or find them at this link) of pregnancy-friendly exercises brought to you by Jacqueline Shahar at 30-weeks pregnant!