I ovulate late in my cycle (i.e. day 16-18 of a cycle of 25-29 days). My doctor feels this may be related to my high fitness level. I usually run, bike or lift weights 45-60 minutes/day. We have been trying to get pregnant for about 11 months now without success. Do you believe cutting back on exercise will increase my chances? Can exercise be making me ovulate late?

--Candi

The ovaries are stimulated by hormones FSH and LH, produced by the pituitary gland at the base of the brain. This gland is in turn controlled by the hypothalamus, which releases a small burst of GnRH about every 90 minutes. When you exercise, your body produces opioids or endorphins, which suppress the hypothalamus, the pituitary and ultimately the ovary. The chance that your menstrual cycles will be adversely affected goes up the more you exercise, the younger you are, the more rapidly you increase your training, and the fewer calories you take in.

You may wish to decrease exercise to three or fewer hours per week and see if that helps. While usually ovulation induction medications are necessary to restore completely normal cycles and fertility, I have recently been successful using an opioid antagonist, Naltrexone, which is far less expensive. The downside is that if you block your opioids, you will lose your runner's high ... but hopefully replace it with a pregnant mom's high.

Note also that excessive exercise can cause a profound loss of calcium from the bones (osteoporosis). You need to ask your doctor if you should be screened for this condition.