Thursday, October 4, 2012

Exercise during pregnancy - a question of intensity..?

When I became pregnant I went on a mission to find some reasonable guidelines as to what I could and couldn’t do in terms of exercise and training. I didn’t know anything about exercise and pregnancy at this point but by enlarge what I did know wasn’t too encouraging. Stuff pregnant friends had been advised rang through my head “you better give up running just in case” one friend and passionate hill runner was told by her GP. “Easy swimming is fine” another assured me or “ Go for brisk walks every day instead of running, cycling etc..”  WHAT?? This was not what I wanted to hear! Brisk walking was not going to produce the levels of exercise-induced endorphins I was used to.

This kind of advice was all well and good for someone who wasn’t too pushed about physical activity, but to someone used to fairly moderate levels of exercise at high intensity it was not what I wanted to hear. I wondered what the hell all the elite athletes at the top end of the scale do? I was sure the likes of Paula Radcliff and Sonia O Sullivan didn’t stop training during their pregnancies. Surely they didn’t just swap running 100 miles a week for easy walks and gentle swimming. I thought I had heard somewhere that Paula in fact had run a marathon while 7 months pregnant in a pretty impressive time!

In my search for information I turned to the 1st port of call for people looking for information on anything – the trusty internet. This turned out to be a bit of a mission. I suspected that the information must be out there somewhere and that most pregnant female athletes must be following some sorts of training programs, but any concrete reference to what they were doing remained elusive. Googling word combinations such as “athlete” and “pregnancy” and “exercise” and variations of the above yielded results with wildly different advice. Everyone who wrote anything seemed to have an opinion and I could not believe how polarized some of these views were. There seemed to be precious little in the way of advice that wasn’t ultra conservative.
Anyway at this point not finding what I wanted, I put the brakes on and took  a different tack. Being a scientist and also a veterinarian I decided the best approach would to conduct my own scientific literature review to look for good robust peer-reviewed journal articles from a range of physiology and medical journals for answers. The results produced slightly less conflicting views on exercise during pregnancy, but by en large I felt were still pretty cautious in terms of advice. The standard set of guidelines that are referred to in most publications were set by the American College of Obstetricians and Gynecologists (ACOG) first in the 1980’s. These have been recently revised but still remain pretty conservative. ACOG recommend that pregnant women who are free of any complications engage in >  or = 30 minutes of moderate physical activity per day on most days of the week.

During my literature search I was astonished to find that in general there has actually been relatively very little in the way of research on the effects of exercise on pregnant women and their unborn babies in the last 20 or 30 years. I came across one recently written article that explained the reason for this - such research is highly contentious and even deemed in some cases to be unethical. Research to investigate the effects of high intensity exercise on the fetus appears to be particularly fraught with ethical complications, and therefore the number of studies investigating such could nearly be counted on one hand with very few participants in each study.  It is worth mentioning here that based on these limited studies there doesn’t appear to be any evidence to indicate that exercise at higher intensities produces any harmful effects on the fetus, which I found particularly interesting. Despite this lack of evidence, one of the most common suggestions when you seek advice about what level you can exercise at during pregnancy is to reduce the intensity! Really though this is not surprising -The precautionary principle is applied across the board when it comes to pregnancy. This as any women who has ever undergone a pregnancy will know is true, not just when it comes to exercise, everything from supplements to medicines to foods and drink, anything that has not been proved conclusively beyond reasonable doubt to be totally harmless – well you better not!! Just in case that is… No one is going to advice a pregnant woman otherwise for fear of the consequences, if there happen to be any. That’s why taking the approach of listening to your body is probably the best advice anyone can get when wondering what they should and shouldn’t do during their pregnancy: if it feels ok – go for it!

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