Aside from the other risks it poses to your health, excess body fat can lead to an overproduction of certain hormones that disrupt ovulation. Your cycles may be less regular, you may ovulate less often, and you lower your chances of getting pregnant. On the flip side, too little body fat means your body may not produce enough hormones to ovulate each month or to sustain a pregnancy if you do conceive. Exercise can help you maintain a healthy weight. Just don't overdo it, says Dr. Christopher Williams, a UVA reproductive endocrinologist and author of “The Fastest Way to Get Pregnant Naturally.”