Over-Exercising & Fertility: What You Need To Know
But can too much be detrimental? Current research on exercise and fertility hasn't reached a consensus on the exact amount that will negatively impact your fertility. However, there's a delicate line. After a certain threshold, too much exercise can impede your ability to become pregnant by affecting your menstrual cycle and ovulation periods.
Defining the workout threshold
There is a difference between moderate and vigorous exercise. Moderate exercise gets your heart beating faster but is more gentle on the body. Typically, you should still be able to speak while participating in the activity. In contrast, vigorous exercise is more physically challenging and exerts more energy. It can become problematic because, ultimately, it places the body under duress.
Over-exercising occurs when you engage in overly strenuous physical activity over a prolonged period. Consequently, exercising in this manner puts the body in a highly stressed state. We naturally produce cortisol, the stress hormone, as a response to exercising. Throughout evolution, cortisol played a vital role in our fight or flight response. Today, it adds an extra boost in energy that makes us feel good after working out.
However, prolonged elevated cortisol levels interfere with the brain's production of reproduction hormones. The body receives imbalances of progesterone and estrogen, which impede its ability to maintain its natural pregnancy cycle. Therefore, the more lengthy and intense your workout plan, the greater chance you'll have consistently increased cortisol levels, which can negatively affect your ability to become pregnant.
The effect on the reproductive system
Exercise-induced infertility is the effect of over-exercising on our bodies. This condition impacts reproduction in several ways by creating hormonal imbalances that produce challenges for conception.
- A 2016 systematic review of ovulation showed a shortened luteal phase, the two weeks between ovulation and your upcoming period, for participants. Normally, the body's progesterone levels are higher to help the fertilized egg attach to the uterus. However, a shorter phase decreases progesterone levels, therefore interfering with egg implantation.
- The body's leptin levels, which regulate your appetite and metabolism, become dysregulated, and this negatively affects your ovulation cycle. Loss of appetite is relatively common and, without proper nutritional intake, ovulation becomes irregular
- Anovulation, which is the absence of ovulation, is more common due to the body's hormonal fluctuations. This gives the woman fewer chances to conceive since eggs aren't released or adequately developed every month.
- Amenorrhea, when you stop having your monthly period, generally occurs in athletes and women who maintain strenuous workout routines. The body goes into a starvation state because the amount of energy expended in exercise is more than the nutritional intake, which causes an imbalance. Without a monthly cycle, the other hormones (estrogen, progesterone, LH, FSH) needed to stimulate the ovulation cycle and promote pregnancy are decreased, further increasing infertility.
If you're already having fertility issues, over-exercising can also aggravate fertility treatments, such as in-vitro fertilization (IVF). A 2016 study conducted by Harvard's Department of Public Health showed that strenuous exercise for four or more hours could reduce your chances of seeing IVF success.
The sweet spot
Exercise is important, but you'll need to maintain a happy medium with your physical activity to avoid fertility issues when trying to become pregnant. The exception to this rule is women who are obese or overweight. They may see an increase in fertility from vigorous exercise. In general, moderate activity is optimal for keeping yourself healthy and boosting your fertility.
- Walking, bicycling and yoga are great examples of light exercise that gets your blood going without overworking the body.
- For routine workouts, it's best to exercise anywhere from one to five hours total in one week. Remaining in this moderate area of exercise will keep you healthy and promote fertility.
- High-intensity workouts such as running, aerobics, powerlifting and CrossFit can increase your chances of infertility the more often you do them. If it's part of your routine, it's best to limit the duration and amount of times you plan on doing that specific exercise per week.
Ultimately, everyone's situation will be different. Women should speak with their doctor about the kind of exercise to do while trying to conceive and ask questions to see if changes are necessary to their workout regimen.
Some women will need to modify their exercise plan, while others will be able to maintain their current routine as they attempt to become pregnant. The bottom line is that your workout routine should be tailored to your needs and concerns, so you can make sure you're remaining active in the most beneficial way.