“You shouldn’t be doing that in your condition!” How many times have you heard these words? If an American woman is pregnant, it seems like everyone’s ready to share their opinions. Whether she’s pushing a grocery cart to hand-digging a well, our society seems obsessed with the idea that bed rest is the best and only solution to a swollen abdomen. Maybe they’re afraid that the baby will just drop if a pregnant woman wiggles too much. Whatever the reason, it’s something I’ve never understood.
It makes no sense to tell someone who’s gearing up for the most intense workout of her life not to move or lift. We certainly don’t give the same information to runners gearing up for their first marathon. In fact, there’s set standards for increasing physical endurance, steadily graduating from high-protein to high-carbohydrate diets, and creating game plans for exact very exact segments of time and geography within the event. After all, you’re using a huge amount of your muscles and energy for the greater part of a day.
Imagine using a huge amount of your muscular energy for more than a day. Imagine working out hard for a day and a half or two days, only in this instance, you are unable to get off the treadmill once you’re completely exhausted. Imagine the treadmill is set to gradually increase in slope and speed until long after you thought you’d never make it a step further. In birth, there’s no getting off when you’re tired.
Fitness during pregnancy has evolved tremendously since the days of dads passing out cigars in the waiting room. Where women were once told to physically exert themselves as little as possible, it is now widely understood that fitness will do more good than harm. That does not go to say that everyone agrees on what “fitness” is. Today, the trend is more toward cardiovascular activity than strength training. This is largely due to the fact that there was enough medical evidence to support a hypothesis that strength training may be detrimental to the developing fetus. And one thing we know about supposed medical contraindications is that testing for research purposes, especially on gestating women, is a very slippery slope for an unethical investigation.
That has changed dramatically this week. On March 26th of this year, Science Daily released an article, “Supervised Weight Training Safe for Pregnant Women, Study Suggests,” highlighting a University of Georgia study focused specifically on strength training. A sample population of 32 pregnant women participated in a supervised strength training program for 12 weeks, while their blood pressure and general comfort were measured against standard norms. One of the potential hazards of strength training has been thought to be increased blood pressure, delivering greater risks of issues such as preeclampsia. However, after 618 training sessions which increased in intensity by an average of 36%, the study found no change in blood pressure.
The study, funded by a grant from the National Institutes for Health, did report some minor complications among the pregnant subjects. Out of all 618 sessions, there were issues with 13; including headache, pelvic pain, and dizziness. Pelvic and/or back pain is often expected, due in part to a dynamic body which is undergoing constant changes during pregnancy. “The one thing you have to be a little careful about is dizziness,” says Patrick O’Connor, a researcher in the UGA study. Dizziness is associated with overheating, that big reason your grandmother told you to stay in bed while pregnant. Dizziness is a sign of dehydration and hyperthermia, both of which have a higher risk of fetal damage during the first trimester. In the event of dehydration, maternal blood volume decreases, which increases oxytocin concentrations in the blood. Oxytocin is something we typically like to see a lot of-in labor. Higher blood concentrations before term can actually promote early labor, which again is the opposite of the desired effect. Further complications of hyperthermia (“overheating”) come up when it’s taken into account that fetal body temperature is always 1 degree Celsius higher than maternal body temp, and babies don’t have the ability to sweat. This is an issue particularly during the first trimester, where greater heat concentrations may inhibit healthy fetal development.
The Science Daily article had more encouraging information to deliver about dizziness than the mere fire and brimstone of subjecting a defenseless fetus to a fiery death of hyperthermia. The study found that maternal dizziness rates actually decrease as the strength training program increases in intensity. O’Connor mentioned that the trend was due to the fact that “…the women learned to lift weights while maintaining proper breathing techniques for exercise.” I find this particularly significant because it highlights the point that a gestating body is not static; women do have the ability to become more physically fit during pregnancy.
It’s an idea supported by the Mayo Clinic as well. Mayo has a lot to offer women in terms of what their physical exercise options are during pregnancy, and in a lot of ways it mirrors the results O’Connor found in his strength training study. In one of that organizations’ articles, “Pregnancy and Exercise: Baby Let’s Move,” women are encouraged to exercise at least 30 minutes a day, 5-7 days a week. The article mentions that athletes, or women who already subscribe to an exercise regimen, need not adjust their regular patterns due to pregnancy. In fact the Mayo Clinic also recommends gradually increasing endurance over the entire course of gestation. Pretty sound advice considering the uterus is the strongest muscle, pound-for-pound, in the human body. For an organ weighing roughly 40 oz, the uterus is able to exert about 100-400 newtons of downward force with each contraction. That’s going to use a lot of energy, and if the laboring mom is in the condition of great physical fitness, her ability to push out a baby after 12-30 hours of exertion is going to be exactly where she wants it to be.
I think Mayo says it best: “Regular exercise can help you cope with the physical changes of pregnancy and build stamina for the challenges ahead. If you haven’t been exercising regularly, use pregnancy as your motivation to begin.”