Exercise: Too Much of a Good Thing?

Women trying to get pregnant may want to reduce exercise to 5 hours a week max


Exercise is good for you, isn’t it? Well, when you’re trying to get pregnant, the answer is “within moderation.” Of course, the definition of “moderation” is the big question.

Exercise can definitely be beneficial when trying to conceive. If you’re overweight, a sensible exercise program along with dietary modifications is of unquestionable benefit.

Obesity can impair fertility, and loosing even 10% of body weight can be on benefit. Exercise can also help cope with the stress of infertility.  Being physically fit will help pregnancy outcomes.

In several research studies, it has been shown that more than five to seven hours per week of aerobic exercise can interfere with fertility. In women going through IVF, as little as four hours of intense exercise may decrease the chance of a successful outcome.

At extremes of exercise and low body weight, the menstrual cycle may stop altogether. This results in not only no ovulation, but also low levels of estrogen in the body.

This can be associated with vaginal dryness and even thinning of the bones.

Also, with low body weight, there is an increased risk of osteoporosis. With decreased exercise and increasing body weight, the menstrual cycle and fertility may return, but MAY never return to normal. This is a situation that if often seen with ballerinas, high-level gymnasts or runners who stop having periods altogether.

At lesser extremes of exercise and caloric restriction, there is a negative impact on fertility even when periods continue. High levels of exercise may cause inadequate progesterone production which makes the lining of the uterus less receptive a fertilized egg implanting.

Exercise may also interfere with the hormones that regulate the female reproductive system in such a way to prevent ovulation. High levels of exercise may also result in weight loss, which may itself interfere with ovulation. It is important to maintain adequate caloric intake and adequate fat intake to balance the exercise expenditure.

So what is the amount of exercise recommended?

Keep track of how much you are exercising. If there is more than five hours a week of intense exercise, decrease the intensity and duration of exercise.

Yoga or walking may be a nice alternative to an intense cardiovascular workout. Make sure that you are eating adequately to compensate for the exercise.

Ideally, body mass index (BMI) should be 20-25 when trying to conceive.  (BMI can be calculated online at http://nhlbisupport.com/bmi/). If your BMI is <20, try and increase caloric intake/ dietary fat intake. Along with the apple a day, you may want a bowl of high fat ice cream a day.