What’s the connection between fertility and exercise?

Exercise is a great activity for reducing stress while keeping fit and healthy. But for those women who are trying to get pregnant, the quality, duration and intensity of a workout may make a difference.

A recent study (via WebMD) suggests that regular bouts of vigorous exercise may delay conception for women who are of normal to average weight (the study found that vigorous exercise didn’t appear to delay getting pregnant for overweight women, however).

That doesn’t mean exercise is out of the question for women of normal weight who want to get pregnant. The study, which was done by researchers at Boston University’s School of Public Health, suggests that moderate exercise is good for women of all shapes and sizes seeking to conceive.

The study defined running, intense cycling, aerobics, gymnastics and swimming as vigorous. Gardening, golfing, brisk walking and riding a bike at a more leisurely pace were considered moderate activities.

How greatly may the type of exercise a woman engages in affect her chances of getting pregnant each month? The study’s finding suggest that those women “who exercised vigorously five or more hours a week were 42 percent less likely to get pregnant in any given month than women who did not exercise at all.”

The study is by no means definitive—it consisted of 3,000 women filling out a questionnaire. Moreover, sitting on the sofa eating chocolates isn’t exactly a boon to fertility either. Yet some health experts advise women who want to have a baby to tone down their exercise intensity.

The WebMD article quotes Texas-based ob-gyn, Robert Brzyski. Brzyski said: “Women who exercise to relieve stress should certainly not stop when they want to become pregnant unless there is a medical reason for doing so. It may be a good idea to cut back some, but physical activity should be encouraged.”