Testosterone and estrogen, two of the main androgens or “sex” hormones,” play critical roles in the human body.  Both genders naturally produce these hormones, but the levels of testosterone and estrogen can vary significantly between men and women.   This variation affects several aspects of athletic performance, physiological adaptations to exercise, and overall health.  In this blog, we will explore the functions of these hormones, what levels experts consider “healthy,” and the implications for athletes.

 

Testosterone

 

Often referred to as the “male sex hormone,” testosterone is responsible for the development of male reproductive tissues and secondary sexual characteristics, including facial hair growth, sperm production, and a deeper voice [1], as well as other important functions that are not exclusive to men.  Specifically, this androgen aids in maintaining bone density, influencing body composition, and erythropoiesis (or red blood cell production) in both males and females [2].  Testosterone also affects mood, cognition, and energy [1]. 

 

Testosterone levels tend to peak during adolescence and early adulthood, gradually declining thereafter [1].  Optimal levels for men are typically around 300 – 1,000 nanograms per deciliter (ng/dL) [4].  In women, testosterone levels are much lower, usually between 15 – 70 ng/dL [4].  

 

Failing to meet your nutrition needs, chronic stress (including stress from exercise), hypothyroidism, pituitary dysfunction, and high levels of body fat may all contribute to low testosterone, leading to symptoms like fatigue, decreased libido, depression, and reduced muscle mass [1], whereas conditions such as polycystic ovarian syndrome (PCOS), in females, cause abnormally high testosterone [1].  

 

Estrogen

 

Estrogen is actually a group of hormones associated with feminine characteristics (i.e., breast development, widening of the hips) and sex-specific functions such as regulating the menstrual cycle and supporting pregnancy [5].  Unrelated to reproductive health, estrogen remains essential for both males and females as it impacts bone density, cholesterol levels, circulation, mood, and glycemic control [5]. 

Labs for estrogen specifically test estradiol, a specific form of estrogen [6], with levels reflecting one’s age and puberty status.  Therefore, what we consider “ideal” is dependent upon several factors such as age, stage of puberty, sex, and individual health variations.  For girls between 9 – 12 years old in early puberty, we expect to see levels around 20 – 100 picograms per milliliter (pg/mL), whereas girls in mid – late puberty (ages 12 – 15 and 15 – 18) will have significantly higher levels ranging from 100 – 300 pg/mL and 200 – 500 pg/mL, respectively [7].   In teen boys, estrogen levels should be a lot lower, at 10 to 50 pg/mL [6].  Amenorrhea in females (or loss of one’s menstrual cycle), stress fractures, insomnia, and mood changes may indicate suboptimal levels [8].  

 

Implications for Athletes

 

Maintaining a healthy balance of testosterone and estrogen is key for athletes looking to maximize their performance and well-being.  

 

For these reasons, it is important to consume sufficient carbohydrates, fats, and proteins to support the body’s natural hormone production.  Proteins and fats play a crucial role as the building blocks of hormones.  Athletes should avoid using anabolic steroids to artificially boost testosterone levels, as high concentrations of this steroid can lead to negative effects like increased aggression and mood swings [1].  Additionally, in females, too much of this hormone may induce a more “masculine” look [1].  When testosterone levels are too low, strength, muscle gains, and athletic performance suffer.   

 

Estrogen plays a crucial role in maintaining bone health, regulating cholesterol levels, and supporting cardiovascular function [8].  Low estrogen levels may result from inadequate energy intake relative to training demands (i.e., as in RED-S and/or anorexia nervosa), posing risks for fractures and osteoporosis [8].  Athletes facing this issue should consult with a registered dietitian or their primary care physician for guidance.

 

Conclusion

 

In short, while testosterone is often associated with masculinity and estrogen with femininity, both hormones are present in both males and females.  Generally male athletes tend to have higher levels of testosterone, while female athletes have higher levels of estrogen; however, age, gender, genetics, training stimulus and intensity, diet, and medications can all cause fluctuations and impact sports performance and overall health.  This highlights the importance of adequate nutrition, recovery, and stress management.

 

 

References

1. LeWine HE. Testosterone — What It Does and Doesn’t Do. Harvard Health. Published July 16, 2015. Accessed July 28, 2024. https://www.health.harvard.edu/staying-healthy/testosterone–what-it-does-and-doesnt-do
2. Cleveland Clinic. Low Testosterone (Low T): Causes, Symptoms, Diagnosis & Treatment. Cleveland Clinic. Published October 4, 2018. Accessed July 28, 2024. https://my.clevelandclinic.org/health/diseases/15603-low-testosterone-male-hypogonadism
3. Testosterone Information . Mount Sinai Health System. Accessed July 28, 2024. https://www.mountsinai.org/health-library/tests/testosterone#:~:text=Normal%20Results
4. Medicine N. Quick Dose: Can Physical Activity Affect Testosterone? Northwestern Medicine. Published September 2022. Accessed July 28, 2024. https://www.nm.org/healthbeat/healthy-tips/fitness/quick-dose-can-physicial-activity-affect-testosterone#:~:text=To%20get%20more%20testosterone%2C%20focus
5. Cleveland Clinic. Estrogen: Hormone, Function, Levels & Imbalances. Cleveland Clinic. Published August 2, 2022. Accessed July 28, 2024. https://my.clevelandclinic.org/health/body/22353-estrogen
6. Estradiol Blood Test Information. Mount Sinai Health System. Accessed July 28, 2024. https://www.mountsinai.org/health-library/tests/estradiol-blood-test
7. Mayo Clinic Laboratories. Estradiol, Serum. pediatric.testcatalog.org. Accessed August 16, 2024. https://pediatric.testcatalog.org/show/EEST
8. Ginta D. What Are the Symptoms of Low Estrogen in Women and How Are They Treated? Healthline. Published January 31, 2017. Accessed July 28, 2024. https://www.healthline.com/health/womens-health/low-estrogen-symptoms#causes
9. Cleveland Clinic. High Estrogen: Causes, Symptoms, Dominance & Treatment. Cleveland Clinic. Published February 9, 2022. Accessed July 28, 2024. https://my.clevelandclinic.org/health/diseases/22363-high-estrogen