Exercise has a profound impact on almost every area of your life, from how you look to how you feel. It’s healthy for your heart and may lower the risk of a variety of chronic health problems and even help to treat some like high blood pressure and type 2 diabetes. It also reduces mental stress. With exercise having such a strong impact on all aspects of physical and mental health, it’s not surprising that it may affect your menstrual cycle, especially if you do high-intensity exercise. What impact does exercise have on a woman’s menstrual cycle?
Exercise and the Menstrual Cycle
Some research shows vigorous exercise causes lengthening of the menstrual cycle so more time elapses between periods. Not all research supports this idea though. A study published in the International Journal of Sports Medicine found no change in menstrual cycle length in 132 women that ran 30 miles per week while another study showed only vigorous exercise lengthened the time between periods. Other research shows women that do high-intensity exercise have more anovulatory cycles, cycles where they don’t ovulate or release an egg.
What about moderate-intensity exercise? One study showed adolescents that burned 600 kilocalories or more per week training at a moderate intensity had more anovulatory cycles. This may partially explain how exercise lowers the risk of breast cancer. Having more anovulatory cycles reduces the amount of estrogen and progesterone breast tissue is exposed to. Encouraging adolescents to exercise early in life, before their first pregnancy, may offer some degree of lifetime protection against breast cancer by reducing exposure of breast tissue to hormones.
The Importance of Good Nutrition for Preventing Menstrual Abnormalities
Having anovulatory cycles may offer health benefits when it comes to lowering breast cancer risk and, possibly, the risk of ovarian and uterine cancer. On the other hand, over-exercising, especially if you’re restricting calories too much can lead to amenorrhea or lack of ovulation with complete cessation of menstrual periods. This happens when the amount of energy you’re burning off significantly exceeds what you’re putting back into your body. That’s why it’s important to consume enough calories when you exercise regularly.
A portion of your brain called the hypothalamus with the help of the pituitary gland is responsible for sending the signal to your ovaries to release an egg. It’s very sensitive to all types of stress including excessive exercise. Overtraining and undereating can also raise your cortisol level. That can interfere with the signals your brain and pituitary gland sends to your ovaries to stimulate ovulation.
When you stop menstruating, you’re at high risk for osteoporosis, regardless of what age you are due to lack of estrogen – not to mention you’ll experience fertility issues. Fortunately, exercise-induced amenorrhea can be reversed in most cases within six months with adequate calorie consumption and cutting back on exercise. The good news is most women who eat enough calories and don’t overtrain won’t experience amenorrhea. If it happens, it’s a warning sign you’re subjecting your body to too much stress by under-eating and training too much.
Increasing calorie intake by as little as 10% and reducing exercise volume by 10% is sometimes enough to restart your periods – but it’s important to see your doctor to make sure excessive exercise and calorie restriction is what’s causing your lack of periods and to monitor your bone density.
Does Exercise Help Menstrual Cramps?
One of the drawbacks of having a period is cramping. Some, but not all, research suggests that exercise prevents or reduces the severity of menstrual cramps. Menstrual cramps are caused by the release of chemicals called prostaglandins and other inflammatory chemicals that cause the uterus to contract. It’s these contractions that lead to the monthly discomfort of menstrual cramps.
One study showed stretching exercises reduced pain duration and intensity in teenage girls experiencing menstrual cramps. At the very least, exercise helps to alleviate stress, partially by releasing endorphins, and stress has been linked with more painful menstrual cramps.
Does Where You Are in Your Menstrual Cycle Affect Athletic Performance?
Based on research published in Sports Medicine, you may be at a disadvantage from a performance standpoint during the mid-luteal phase of your cycle, the week before your period is scheduled to start. That’s when progesterone levels are highest. At this time your body temperature runs a little higher and your heart has to work a little harder during an endurance workout. You may find it feels a little harder or you have to stop a little sooner around this time. All in all, where you are in your menstrual cycle doesn’t have a major impact on exercise performance.
The Bottom Line?
Exercise has a positive impact on your health and on your menstrual cycle by relieving stress and lowering your lifetime exposure to estrogen and progesterone, thereby lowering your risk for breast cancer. The key is not to overtrain or restrict calories too much. If you do, you may experience fertility issues and loss of bone density. Exercise hard but smart – and make sure you’re getting proper calories and nutrition.
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