So I was surprised, and somewhat skeptical, when I received a news release about a “first of its kind” study that had determined that resistance training — strength training in its various forms — can be beneficial to mother and child and shows no correlation to complications during pregnancy.
Didn’t we know that already? It’s 2011. A lot of pregnant women lift weights.
It turns out we really didn’t. “There isn’t a ton of medical research” on resistance training during pregnancy, said George Macones, chairman of the committee that wrote the guidelines for exercising during pregnancy for the American College of Obstetricians and Gynecologists. In fact, that policy statement, written in 2002 but reaffirmed periodically since, contains nothing about strength training. Neither do government recommendations on exercise during pregnancy.
“Forgive the pun, but we’re at baby steps” on this subject, said Jim Pivarnik, a professor of exercise physiology at Michigan State University who supervised the new study, which is the ongoing doctoral dissertation of a student, Erin Kuffel. The bottom line, Pivarnik said, is that although many women keep strength training well into their pregnancies, there really are no good, specific recommendations for them on how much to lift, how often, at what intensity and when to slow down, he said.
“We haven’t been studying it,” Pivarnik said.
Usually such decisions are made individually between patient and doctor, and physicians may have little or no experience with strength training, he said. “That’s a medical school issue,” he said.
Pivarnik and Kuffel worked with the Anytime Fitness chain to study 214 women, 57 of whom used free weights, weight machines or other strength training methods about three times a week for 30 minutes during their pregnancies.
The strength training group showed no difference from those who did no resistance work in maternal weight gain, gestational age at delivery, length of infant at birth and birth weight (which confirmed previous controlled studies by other researchers on similar issues). And they may have achieved small benefits in weight control and reducing the risk of gestational diabetes and hypertension, the research found. The study is continuing.
It’s not as if pregnant women have been flying blind on weight training. The Internet is full of articles on the subject, and if it’s not always clear whether the advice is trustworthy, there is always the guidance of a trainer, nurse practitioner or obstetrician. Health professionals may have to speak more generally than trainers on the topic of exercise, but they have good firsthand knowledge of their patients’ needs.