Stretching Beats Walking To Prevent Complications of PregnancyFriday, August 12, 2011
Preeclampsia, a potentially life-threatening complication of pregnancy, is more common in women with excess weight and there is now considerable evidence that the risk for this problem can be reduced with exercise.
Interestingly, a previous randomised-controlled intervention in 124 pregnant women reported that simple stretching exercises, consisting of slow muscle movements that had neither aerobic nor muscle resistance components, performed 5 times a week starting at 18 weeks of gestation, very impressively reduced the risk of early signs of preeclampsia, compared to walking 40 mins 5 times a week (2.6% versus 14.6%).
Now, a paper just published in the American Journal of Perinatology by Sowndramalingam Sankaralingam and colleagues from the University of Alberta, suggests that this difference may be due to a more positive effect of stretching exercises on reducing oxidative stress in blood vessels of these participants.
Immunohistochemical analyses of blood vessels embedded in fat biopsy samples obtained during cesarean sections from some of the women who were randomized to either stretching ( N = 6) or walking ( N = 5) exercises in this larger study, showed remarkably higher expression of the antioxidant superoxide dismutase (SOD) and plasma transferrin levels, an antioxidant marker.
In addition, plasma levels of transferrin continued to increase throughout gestation only among the stretchers.
Thus the authors conclude that the beneficial effect of regular stretching exercises during pregnancy not only trump the benefits of walking may be attributable to the higher antioxidant protective effect of this low-intensity exercise during pregnancy.
Incidentally, in the original study, walkers tended to exercised less than stretchers both overall and as pregnancy advanced, suggesting that stretching may be a better intervention as it is easier to perform and adhere to during pregnancy.
While neither stretching nor walking had any effect on body weight, it is certainly worth considering that stretching exercises should perhaps be routinely prescribed and encouraged in women at risk for preecmlampsia.
Sankaralingam S, Jiang Y, Davidge ST, & Yeo S (2011). Effect of Exercise on Vascular Superoxide Dismutase Expression in High-Risk Pregnancy. American journal of perinatology PMID: 21815126
Friday, August 12, 2011
Thanks so much. Now, this is the kind of information that is going to improve the health of fat people. Really, really helpful.
Another couple that I think would be really nice to see:
1. Exercises to strengthen the muscles around joints.
2. Nutritional deficiencies that are more common in fat people, the symptoms, and how to mitigate them (for example, through foods, supplements, sun exposure…)
…and basically anything that addresses the health risks associated with being heavier than average directly rather than via “lose 50 pounds and call me in the morning.”
One question, though. Did they have a group that did both (walk and stretch)? I wonder how that would affect risks.
Friday, August 12, 2011
Dear Dr. Sharma,
I have to disagree with your recommendations based on this study. While the topic is extremely important and may warrant further investigation, this particular study has significant limitations.
First, this study included a very small number of participants (n=11) who were either diagnosed with preeclampsia in a previous pregnancy OR were at risk for developing preeclampsia (ie. Sedentary, low aerobic capacity, obesity). Previous research has clearly demonstrated that women with a history of preeclampsia, even if they do not have preeclampsia in the index pregnancy have long-term persistent alterations in their vasculature. This was not controlled for in this study.
Obesity has been linked to increased oxidative stress. The women in the walking group were ~25kg heavier than the stretching group. Although this was an important covariate, it was not controlled for in this study.
Suggesting that stretching rather than walking should be prescribed to women who are at risk for preeclampsia (ie. Women who are overweight or obese prior to pregnancy) ignores a large body of literature that has shown the benefits of lifestyle interventions in preventing excessive weight gain and it’s associated maternal/fetal consequences in this population.
Dr. Margie Davenport
Sunday, September 4, 2011
As the principal investigator of the two studies mentioned on your site, I would like to comment in response to Dr. Davenport.
I agree with Dr. Davenport in principle, except that suggesting stretching exercise for at-risk pregnant women does not prohibit healthcare providers from suggesting/recommending sensible diet to limit weight gain within the IOM recommendation. Indeed, if anything our studies taught me, it was a need for a comprehensive lifestyle intervention embracing diet, exercise (stretching or other low intensity exercises) and stress management, which may improve oxidative stress profile and cardiovascular risk thus reduce preeclampsia risk.
Because of a small number of subjects available for this study, it was inappropriate to statistically control weight on the outcomes. I am also interested to know what information we could generate by controlling for vasculature alteration, given a justifiable method for measurement is available in clinical trials.
SeonAe Yeo, RNC, PhD