Low testosterone (low T) levels are never good. Clinically low testosterone leads to poor muscle mass development, increased body fat, and compromised athletic performance. It is also associated with increased risk of certain diseases—osteoporosis, diabetes, and cardiovascular disease to name a few.
It’s safe to say that optimizing testosterone is a top priority, which is why you need to know about these five common causes of low T. It should be noted that this article is geared toward men, however, reductions in testosterone and the related reproductive hormones FSH and LH are also a major problem for women. Therefore, the information presented here is relevant for both men and women.
Possible Cause #1: Poor Insulin Sensitivity
The exact relationship between insulin and testosterone is complex, but we do know that high insulin levels are associated with lower total testosterone and increased body fat. Furthermore, T is temporarily reduced anytime you experience a blood sugar spike.
One study found that among healthy men with normal insulin levels who consumed a drink containing sugar, 80 percent had their testosterone drop to levels that would be considered clinical testosterone deficiency. On a related note, poor insulin sensitivity is associated with body fat, and we know that the more body fat you have, the more aromatase you will produce, which leads testosterone to be transformed into estrogen, further lowering your T level.
Solution: Eat high-quality protein, healthy fats, and low-glycemic carbohydrates like vegetables and low-sugar fruits. Steer clear of refined carbs and junk food, but if you do eat foods that elevate blood sugar, pair them with foods that help moderate insulin and glucose—the herb fenugreek has been found to produce a lower glucose response when it is baked in whole grain bread or added to oatmeal. Berries and nuts have also been found to aid in lowering the glycemic response to high-carb foods.
Possible Cause #2: Nutrient Deficiency: Zinc, Magnesium, Vitamin D
For optimal testosterone production, the body requires sufficient levels of certain nutrients. Zinc acts directly on the testes and ovaries to stimulate the production of LH, the main precursor to testosterone release.
Vitamin D supports T production because there are vitamin D receptors on the cells in the glands that release T. In addition, vitamin D is believed to inhibit the transformation of T into estrogen. Finally, magnesium plays a role in overall hormone balance and appears to improve T release by enhancing your cells sensitivity to insulin.
Solution: A healthy, whole foods diet that is rich in fish, meat, vegetables, fruit, and nuts will set the stage for avoiding nutrient deficiencies. Supplementation is also beneficial for many people, and in the case of vitamin D, it’s necessary unless you get regular sun exposure.
Possible Cause #3: Excessive Stress
In the body, hormones function in a cascade-like fashion, such that the elevation of one hormone will affect many others. In the case of stress, your body pumps out the stress hormone cortisol, which releases fuel stores and breaks down muscle tissue, which is the opposite of what testosterone does.
Additionally, both testosterone and cortisol are steroid hormones, meaning they are made out of cholesterol in the body. When your body is chronically pumping out cortisol in order to get you through high-stress times, the raw materials for producing testosterone will be depleted, thereby lowering T levels.
Solution: Practice smart stress management—focus on complete recovery from training, prioritize good sleep, and adopt a deep breathing or meditation practice to get you through those days when nothing seems to go right.
Possible Cause #4: Too Much Endurance Exercise
Studies consistently show that high-volume endurance exercise reduces T and the related androgen hormones that act as precursors for T (LH and FSH) . At the same time, endurance exercise leads to large elevations of cortisol, which causes adrenal gland enlargement over the long-term. Side effects of low T caused by excessive endurance exercise include low bone density, inability to recover from training, and reduced exercise performance.
It should be noted that recreational running consisting of a few miles on most days of the week is unlikely to cause low T. Athletes who are most at risk are those training a high volume (intense workouts lasting longer than an hour). Marathoners, triathletes, serious CrossFitters, and long distance runners are most susceptible.
Solution: Dial back your volume in favor of weight lifting and brief, interval style conditioning workouts. This approach will target your neglected type II muscle fibers to make your faster and more powerful, without compromising endurance. Focus on smart recovery practices and be sure to get plenty of healthy fat and complex carbs in your diet.
Possible Cause #5: Too Much Alcohol
Alcohol increases activity of the enzyme aromatase that transforms T to estrogen. This, along with the excess calories supplied in alcohol, often leads to fat gain, generally around the abdominal area. Of course, fat secretes aromatase as well, further exacerbating the problem and creating a spiraling effect of T turning into estrogen, causing fat gain, and greater release of aromatase.
Solution: Avoiding alcohol altogether is one approach that most people don’t like. Beer may be more estrogenic and it is certainly linked with belly fat gain in men, so avoiding beer in favor of wine is probably the best alternative. Try to limit intake to one drink with food daily.
Araujo, A., et al. Clinical review: Endogenous testosterone and mortality in men: a systematic review and meta-analysis. Journal of Clinical Endocrinology and Metabolism. 2011. 96(10):3007-19.
Chang, C., Choi, J., Kim, H., Park, S. Correlation Between Serum Testosterone Level and Concentrations of Copper and Zinc in Hair Tissue. Biological Trace Element Research. 14 June 2011. Published Ahead of Print.
Hackney, Anthony. Endurance Training and Testosterone Levels. Sports Medicine. 1989. 8(2), 117-127.
Hackney, Anthony. Testosterone and Reproductive Dysfunction in Endurance-Trained Men. Encyclopedia of Sports Medicine and Science. International Society for Sport Science. 20 Sept 1998. http://www.sportsci.org/encyc/testosterone/testosterone.html. Retrieved 1 May 2015.
Lac G, Berthon P. Changes in cortisol and testosterone levels and T/C ratio during an endurance competition and recovery. Journal of Sports Medicine and Physical Fitness. 2000. 40(2), 139-44
Laughlin, G., et al. Low serum testosterone and mortality in older men. Journal of Clinical Endocrinology and Metabolism. 2008. 93(1):68-75.
Lerchbaum, E., et al. Combination of Low Free Testosterone and Low Vitamin D Predicts Mortality in Older Men Referred for Coronary Angiography. Clinical Endocrinology. 2012. 77, 475-483.
Lee, D, Tajar, A., et al. Association of Hypogonadism with Vitamin D Status: The European Male Ageing Study. European Journal of Endocrinology. January 2012. 166, 75-85.
Maclean, C., et al. Effect of the Transcendental Meditation Program on Adaptive Mechanisms: Changes in hormone Levels and Responses to stress After Four Months of Practice. Psychoneuroendocrinology. 1997. 22(4), 277-295.
McArdle, WD., Katch, FI., Katch, VL. Exercise Physiology. Eighth Edition. Baltimore: Wolters Kluwer Health. 2015.
Neek, L., Gaeini, A., Choobineh, S. Effect of Zinc and Selenium Supplementation on Serum Testosterone and Plasma Lactate in Cyclist After an Exhaustive Exercise Bout. Biological Trace Element Research. 9 July 2011. Published Ahead of Print.
Pilz, S., Frisch, S., et al. Effect of Vitamin D Supplementation on Testosterone Levels in Men. Hormone and Metabolic Research. 2011. 43, 223-225.
Safarinejad, M., et. al. The effects of intensive, long-term treadmill running on reproductive hormones, hypothalamus– pituitary–testis axis, and semen quality: a randomized controlled study. Journal of Endocrinology. 2008. 200, 259-271.