by Dr. Barbara Osborn, MD
How much exercise is OK while I’m trying to get pregnant?
This is a common and logical question our patients ask. Based on the existing literature, however, stating the link between exercise and fertility is a difficult to say with certainty.
Some facts have been well established.
1. Intense physical activity, such as that of competitive female athletes, can disturb the menstrual cycle, but moderate activity has little effect on the cycle.
2. Obesity is associated with decreased fertility. Weight loss in obese women can improve their fertility. Weight loss can also improve menstrual regularity in obese women with PCOS.
What about women with normal cycles?
There are two large studies looking at women who were about to start trying to conceive. Both used questionnaires to ask women about their level and duration of physical activity or exercise before they started trying to conceive.
One of these studies was published in May 2012 looking at 3,628 women in Denmark who were planning for conception. In normal weight women, vigorous activity (running, fast cycling, aerobics or gymnastics) was associated with decreased fertility. Moderate activity (brisk walking, leisurely cycling, gardening or golfing) was associated with modestly improved fertility. In overweight and obese women, however, both moderate and vigorous exercises were associated with improved fertility.
A similar study of 3,887 women was conducted in Norway (published 2009). These women were mostly normal weight (mean BMI 22.7). This study also found that women with the highest frequency, duration and intensity of physical activity were less likely to conceive. When looking just at duration of activity, both short (< 15 min/day) and long duration (> 60 min/day) were associated with decreased fertility, but those with moderate duration (16-60 min) had improved fertility.
Unfortunately, neither study asked the women what their activity was like while they were actually trying to conceive, only what it was before they started. These studies do suggest that exercise in moderation is best for normal weight women trying to conceive, but that overweight women might improve their odds with more vigorous exercise.
Exercise and Fertility – What is recommended for women in fertility treatment?
A small study performed in Turkey was published in 2009. This looked at 131 women about to start their first IVF cycle and evaluated activity both before and during the cycle. Although women were advised to just continue their normal activity, they had a tendency to decrease their physical activity during treatment. While 15 women met criteria for “high” activity before the IVF cycle, none of the women had high activity during the treatment cycle itself. There were 68 women who had low activity during the cycle and 63 with moderate activity. The mean BMI in both groups was 24.7. Moderate activity during treatment was associated with a significantly higher live birth rate (47.6%) than low physical activity (19.4%). Interestingly, the amount of activity the patients were doing before they started treatment had no correlation with live birth rate.
In summary, we have very little data on which to state a link between exercise and fertility. From the available studies, however, it seems that moderate activity such as walking and leisurely cycling seems to make the most sense for women trying to conceive naturally or through fertility treatment.
At Shady Grove Fertility, once a patient has had her IUI or embryo transfer, we suggest that she treat her body as if she is pregnant, recommending gentle to moderate exercise.
To schedule a New Patient Appointment with Shady Grove Fertility please call 1-877-971-7755 or click here.
