Fit to Be a Mom? How Exercise Affects Your Fertility

Expert Advice to Boost Your Fertility

The default stance -- mostly because there have been no controlled studies of exercise in women who are trying to get pregnant naturally -- is that normal-weight women should work out at the "public health" dosage of 150 minutes weekly, says Sheila Dugan, MD, chair of the American College of Sports Medicine's Strategic Health Initiative on Women, Sport, and Physical Activity. That translates to 30 minutes of moderate-intensity activity (you break a sweat and are winded but can still speak in short phrases) five days a week. Under- or overweight women should seek evaluation from a certified fitness professional, like an exercise physiologist or trainer, to tailor a program based on their energy input and output, Dr. Dugan says.

Some specialists are going beyond this generic mandate. Here's what several top docs recommend for their patients and FITNESS readers.

There is no need to give up your regular runs or, say, Zumba classes. Just keep your workouts to an hour or less a day. If your cycle is irregular or you haven't conceived after a few months, cut back further on exercise. Also, this isn't the time to train for your first competitive event or start a rigorous gym class. "If you make a dramatic increase in your exercise level, even if BMI or body fat percentage stays the same, the stress can have a negative effect on reproductive hormone production and fertility," Dr. Brzyski says.

Aim for 2,400 to 3,500 calories a day to gain the weight that will get you into the normal BMI range, or body fat above 12 percent. If you're exercising five or more days a week, consider cutting back to three. Alice Domar, PhD, executive director at the Domar Center for Mind/Body Health at Boston IVF, says hatha yoga appeals to many women in this category: "It keeps them fit and toned without the potential adverse impact of vigorous exercise."

Trim calories and gradually up your exercise to reach a fertility-friendly BMI. Aim for 60 minutes of cardio five days a week, and strength-train for 30 minutes three times a week. Even so, "you can work out too hard even if you're overweight," Dr. David cautions. "Build up your tolerance slowly."

Talk to your doctor before you step on that treadmill. Intense, vigorous or high-impact exercise may cause ovaries that have been enlarged by the use of fertility drugs to twist -- a medical emergency.

So where does all this leave me? Parting with my favorite butt-kicking Spinning class was bittersweet. But nearly two years into our baby mission, I was running out of options, so I decided to scale back my routine. Now I run four miles three days a week and do a light weight-lifting routine twice a week. I switch to the stationary bike for my cardio fix during the second half of my menstrual cycle to avoid the pounding of running during and after ovulation. My body's a little softer, but my jeans still fit and my endo-induced cramps aren't half as bad as I thought they would be. Scott and I aren't buying diapers yet, but we realize that my body is a tricky one to figure out. Still, I have to believe that every little change counts, as long as it doesn't mean any more belly rubdowns from a fertility goddess.