Any irregularity in a woman's period can be disturbing and cause alarm. Spotting after strenuous exercise is usually not a signal of anything serious. For the most part, health professionals do not worry about an occasional missed period or breakthrough bleeding. In some cases, however, it is important to seek the advice of a medical professional to rule out any serious conditions.
Normal menstruation occurs every 21 to 35 days, according to the Mayo Clinic. Any bleeding outside of this cycle is considered irregular bleeding. Some women do find that they experience spotting after intense exercise. Usually, this spotting is light and brownish---rather than a heavy flow like a full period. Spotting during strenuous exercise is not common. Exercise usually affects the cycle by causing irregular periods.
Spotting might seem to be caused by exercise but it could be occurring for another reason. Pregnancy, especially during the implantation phase, and mid-cycle ovulation are common reasons women spot. Women also experience spotting after sex and when changing their birth control.
If it is determined that spotting during exercise is not from another cause, it could mean the body is being stressed too much. A one-time spotting episode will not affect your system seriously, but if it is a regular occurrence you should look to moderate your fitness routine. Spotting could be a sign that you are asking too much of your body.
Ease up on your workouts slightly and see whether, in the course of a few months, the spotting subsides. Observe whether you are also suffering from other symptoms of over-training, such as increased resting heart rate, depression, disinterest in workouts, diminished strength or endurance and unexplained weight loss. If over-training seems likely, you'll need to avoid exercise for several days.
Spotting during pregnancy, especially after exercise, requires immediate consultation with a medical professional. Abnormal bleeding can also be a sign of some types of cancer, hypo thyroidism, polycystic ovarian syndrome and endometriosis. Heavy bleeding induced by exercise should be brought to the attention of your gynecologist.