Excessive Exercise and Infertility

How Strenuous Exercise impacts Female Infertility:

1. Athletic performance can lead to loss of periods

Menstrual dysfunction is experienced by many female athletes who can sometimes experience irregular periods, or complete loss of periods. Overtraining, stress, dieting, and rapid weight loss can cause disregulation of hormones. In fact, the loss of a period from expending more calories than are taken in can cause a drop in athletic performance for women. That's because lower energy levels, lack of sleep, poor nutrition or not enough caloric intake can create stress in the body. In a study from 1999, researchers found that 5% to 25% of female athletes will experience amenorrhea. Unfortunately, if a woman is not having regular periods, she is unable to get pregnant because the ovaries stop releasing eggs, and will likely miscarry or experience complications during a pregnancy.

2. Luteal phase defects

When women experience irregular periods or hormonal imbalances, they may not be able to produce a menstrual lining inside the uterus that is thick enough to support a pregnancy. According to this study, 58% of regular runners and 9% of sedentary women were impacted by luteal phase defects.

Generally, this comes on as an overexpenditure of energy compared to energy intake (nutrition). This is why many diets that promote low caloric intake are not recommended by health coaches who understand that 1500 calories may help you drop weight in the short-term but have negative impacts long-term. Severe caloric restriction is a big no-no if you ever want to become pregnant.

Similarly, vigorous exercise in healthy women is not recommended if they are trying to conceive. Switching to a more moderate routine is more beneficial.

3. Exercising vigorously for more than 2 hours a week

Hitting the gym hard seems like a recipe for rapid transformation. While that may work when you are younger than 40 to slim down, it has been linked to lower fertility in women. For women who exercise vigorously from 2 to 5 hours a week, there is a decrease in fertility ranging from 16% to 32%. But for women who exercised moderately for 2 hours a week, there was an increase in fertility of 15%!

Less is more when it comes to exercise. You do not need to kill yourself in a gym to experience the health benefits of regular exercise. Walking, lifting weights, and light cardio is enough to stay fit in more ways than one.

4. PCOS infertility and impact of exercise

For women who are diagnosed with Polycystic Ovarian Syndrome (PCOS), they will experience irregular periods that will decrease their ability to get pregnant. However, when these women added vigorous activity for 90 minutes a week, they were able to increase their chances of getting pregnant by 7% because their periods became regular.

Compared to advice given to healthy women about moderate exercise, vigorous activity had better results for overweight women with PCOS. In simpler terms, aerobic exercise 3x a week for 30 minutes and doing something vigorous (60-80% of perceived rate of exertion) reduced infertility in women with PCOS. To see the benefits of exercise, it is recommended that women find an exercise program that they enjoy doing long-term. Even if weight doesn't change, the ability to conceive is increased in women with PCOS who exercise compared to diet changes alone.

How Strenuous Exercise impacts Men's Infertility:

1. Oxidative Stress on sperm viability

Men who compete at an elite level like triathalons, marathons, sports, or engage in strenuous exercise will experience oxidative stress (OS) which impacts the viability of sperm. OS can cause DNA damage and lead to sperm death. While competing at an elite level is prestigious in its own right, it can have negative health effects later on in life. 

Moderate exercise can counter OS. Doing lower impact workouts like weight lifting or steady state cardio can have an antioxidant effect to limit the damage to sperm.

2. Male hormone imbalances

Another issue with strenuous exercise is that it can cause cortisol levels to go up. This leads to inflammation in the body. Other hormones can decrease including Luteinizing hormone (LH), and Follicle-stimulating hormone (FSH), and Gonadotropin hormone-releasing hormone (GnRH) which are required for sexual development of the reproductive system in both men and women. Imbalances can lead to developing hypogonadism in men where hormone production can be reduced or eliminated altogether. Prolactin can increase with vigorous exercise causing testosterone production to be blunted.

All of this has severe impacts on infertility in men and testosterone replacement therapy may be required to bring hormone levels back up.

3. Erectile Dysfunction

Competitive athletes like bicyclists, rowers, and long distance runners can experience sexual health issues including erectile dysfunction (ED). Tiredness and fatigue can lead to a lack of libido and reduction in sexual desire. That can make it impossible to maintain an erection. Endurance athletes will experience ED at a higher rate than sedentary individuals.

4. Testicular temperature and microtrauma

To produce viable sperm, testicles must be 2.5°C below core body temperature. With excessive exercise, core temperature rises but so does scrotal temperature. This impacts the quality of sperm significantly. Moderate exercisers do not have the same issues and their temperature is not as impacted.

Similarly, competitive bicyclists can experience microtrauma and nerve damage as part of their long distance training. Abnormalities in the testicles can lead to infertility.

Moderate exercise is the key to fertility in healthy individuals

Overtraining in regular healthy adults is common when they don't have expert guidance to help them understand the effects of moderate to vigorous activity on health, especially for fertility. We think that pushing ourselves really hard at the gym is going to get us gains, however there could be losses in other areas of our health when we are excessively training. 

Working out with a Rage Fitness trainer will set you on the path to success. Book a free demo session, or call/text us at 1-825-945-7733, or fill out the online contact form today!