Can Exercising & Dieting Cause Your Period to Be Late?

During your reproductive years, many life events can alter your menstrual cycle, including pregnancy, breastfeeding and perimenopause. Your hormones fluctuate as you get older, and you may find that your periods gradually or suddenly become closer together or further apart. Weight fluctuations, often caused by dieting and exercise, can also cause your periods to be late or absent.

Rapid weight loss from exercising and dieting can cause irregularities in your menstrual cycle, including skipped or late periods. Estrogen production can vary based on your weight, and lower estrogen levels can affect your periods. Late or absent periods are particularly likely if you have a very low body fat percentage, less than 17 percent, according to MedlinePlus. If you are overweight or if you have polycystic ovary syndrome, however, you may find that losing weight regulates your cycle and makes your periods come on time. Again, this is due to hormone irregularities that resolve themselves when you approach a healthier weight.

Female athlete triad is a syndrome that includes missed or absent periods, disordered eating habits and osteoporosis. It affects girls and women who train strenuously for sports. It is more common in athletes who participate in activities with weight classes, such as rowing and martial arts, and also those whose chosen sports require a lean body shape, such as gymnastics, diving and ballet. Compulsive exercise can cause a low body-fat percentage and also puts stress on the bones and muscles. Because one component of female athlete triad is unhealthy eating habits, seek help if you feel that you cannot control your dieting or that you are losing too much weight.

Teens who exercise and diet a lot or who are underweight may experience delayed puberty. Most American girls begin puberty by the age of 13, according to KidsHealth.org. Teens without enough body fat may not begin to develop breasts or get their first periods at the time their peers do. In some cases, this is not anything to worry about, but in other cases, it could be a sign that the teenager should see an endocrinologist. If your teenage daughter has not yet started puberty, talk to her pediatrician.

Even if you are dieting and exercising, do not assume that missed or delayed periods are necessarily because of weight loss. While a missed period is not usually indicative of anything serious, persistently irregular or missed periods warrant a medical evaluation. In some cases, it could mean you are losing too much weight too quickly. Other reasons for late periods may be hormonal disturbances, thyroid problems or problems with your reproductive organs, such as polycystic ovary syndrome. A missed period could also indicate pregnancy. See your physician if you have skipped more than one period.