When you’re trying to conceive, you may wonder how exercise affects fertility. This is a simple question with a somewhat complicated answer that depends on many individual factors. So the first piece of guidance is to discard any “one size fits all” advice you may have heard because no one recommendation is right for All.
Another point to remember is that Exercise offers a number of wonderful benefits for parent and child, so if you can exercise to any degree, it is highly recommended.
To address the complexities surrounding the topic of exercise and fertility, this article provides findings from current research so you can make the most informed choices for you and your family. In addition, it is important to listen to the instructions offered by your doctor, who will have the most complete picture of your health profile and needs.
NOTE: This article uses gender-specific language because that is the convention used in research.
What is infertility and its causes?
Infertility defined as a couple’s inability to conceive within one year of trying to get pregnant through unprotected sex.
According to the latest World Health Organization report as of April 2023, Infertility affects 1 in 6 couples worldwideand this statistic persists among high- and low-income populations (WHO, 2023).
The causes of infertility are equally attributed to female and male factors. Female factors include disorders of the fallopian tubes, uterus, and ovaries (ie, endometriosis, fibroids, PCOS) as well as endocrine system imbalances (some of which will be discussed in the next section). Male factors include low sperm production and quality as well as ejaculation difficulties.
Because infertility is relatively common, efforts to understand modifiable lifestyle factors are of interest. Exercise falls into this category, so let’s look at how exercise affects fertility.
How does exercise affect fertility?
Overall, staying active and fit is far more beneficial than being sedentary. However, it is important to bear in mind that physical activity exists on a spectrum and it appears that its effects on fertility can be “positive up to a certain level and has a negative effect above this threshold level of activity” (Gudmundsdottir, et.al, 2009).
But these effects depend in part on the woman’s body mass index (BMI) before pregnancy. If a woman is starting to be overweight or obese, exercise can improve fertility outcomes. If a woman is underweight or “normal” weight and engages in more vigorous activity, then exercise can restrict fertility outcomes.
The mechanism behind the poorer results has to do with effects on the endocrine system. Exercise is a type of stressor, and when that stress exceeds a certain level—repeated, longer sessions of vigorous exercise—it can lead to reduced energy balance (more calories than in), which reduces female reproductive capabilities ( Warren & Perlroth, 2001). .
In the research, this was especially true for athletes participating in sports that have an aesthetic component (eg, gymnastics, dance), likely due to the pressures of keeping body fat and weight low.
This idea that high-calorie-burning activities are harmful also applies to men. A high volume of sustained physical activity, which has a significant caloric cost, may be accompanied by a transient suppression of reproductive function in both men and women (Redman, 2006). Oxidative stress, which comes from more intense exercise (as well as caloric deficit) negatively affects sperm count. Endurance activities (eg, cycling, running) appear to be the most well-associated type of exercise that reduces sperm count and may increase the incidence of erectile dysfunction.
How can you maximize your fertility results?
It seems that Moderately active men and women have the best reproductive function and fertility outcomes. Extremes at either end of the activity spectrum appear to reduce fertility. So take a balanced approach. Exercising while trying to conceive is a smart choice as long as both partners are careful to avoid long bouts of vigorous exercise (>60 minutes of high-intensity or high-calorie activity).
Please note that these recommendations are only for the time you are trying to conceive. If your body is used to higher intensity exercise, you can return to it once you’ve been cleared by your doctor (usually 1-2 months after successful fertility treatments). Just relax again so your body has a period of adjustment before increasing the intensity.
Can exercise cause miscarriage?
If you’ve struggled with infertility, it’s natural to worry about the risk of miscarriage as well. For information on the relationship between exercise and miscarriage, see this post Exercise can cause miscarriage?
Want additional resources?
For additional resources to help you exercise safely and Efficiently during pregnancy, explore us educational programs and services. You’ll find a variety of offerings tailored to different needs — from training, to self-directed programs, to the ability to work with an experienced coach.
Or, if you are a health and fitness professional interested in coaching pre and postnatal clients check it out ProNatal Training & Certification.
Sources
Gudmundsdottir, SL, Flanders, WD, & Augestad, LB (2009). Physical activity and fertility in women: the North-Trøndelag Health Study. Human Reproduction, 24(12), 3196-3204.
Morris, SN, Missmer, SA, Cramer, DW, Powers, RD, McShane, PM, & Hornstein, MD (2006). Effects of lifelong exercise on IVF outcome. Obstetrics and Gynecology, 108(4), 938-945.
Redman, LM (2006). Physical activity and its effects on reproduction. Reprod Biomed Online12, 579-586.
Warren, MP, & Perlroth, NE (2001). Hormones and sport-the effects of intense exercise on the female reproductive system. Journal of Endocrinology, 170(1), 3-12.
World Health Organization, (2023, April 3). Infertility.
World Health Organization, (2023, April 4). 1 in 6 people worldwide is affected by infertility: WHO.
