Testosterone is essential for men’s (and women’s) health. If you ask most men what the role of testosterone is in the body, they’ll likely say it builds lean muscle and boosts libido. While this is certainly correct, testosterone’s benefits go far beyond this. Healthy testosterone levels are critical for fighting off depression, maintaining healthy blood sugar levels and preventing metabolic syndrome, keeping your heart healthy and bones strong, as well as overall vitality.1,2,3 In fact, as men get older, optimal testosterone levels are associated with reduced “all-cause mortality,” a fancy medical term for death by any cause.4
Testosterone levels naturally decline steadily as you age, typically at 1-2% per year after the age of 40. However, with obesity and diabetes levels reaching all-time highs, it seems the trend of low testosterone is more common today than years past, and a result of our modern lifestyle.
If maintaining healthy testosterone levels is good for your muscles, libido, and anti-aging, it seems to make sense that you should just supplement, right? Not exactly. The normal range for testosterone levels varies dramatically. In healthy adult males, it’s between 315 and 1,000 ng/dL.5 Most men struggling with some (or many) of the symptoms of low testosterone think a cream or gel is the solution to their problems. Unfortunately, it’s not that easy. Only 10% of adult men are two standard deviations away from the norm, meaning only one out of 10 may see benefits from supplemental testosterone, and this rate only climbs to 20% past the age of 60.6
If your testosterone levels are low, it seems logical that adding more into the system to raise your levels will fix the problem. Unfortunately, this just treats the smoke (i.e. the symptoms) and not the fire (i.e. root cause). Testosterone creams and gels are heavily prescribed today, yet they fail to produce meaningful results and often make things even worse in the long run. The typical result is that guys will feel great for the first 4-8 weeks, then not only do their initial symptoms return, they’re often worse than where they started!
In short, you don’t need to “boost” your testosterone, but rather focus on removing all the roadblocks hampering your ability to adequately produce testosterone. Let’s do a quick review of testosterone physiology, then I’ll address seven common reasons for low T.
Physiology of Testosterone
Testosterone production starts in the brain. Your hypothalamus is the ‘master conductor,’ leading the orchestra of hormonal reactions in the body. It secretes
gonadotropin-releasing hormone (GnRH) in a pulsatile fashion, stimulating the release of both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary, which then travel to the testes.7 LH acts on the Leydig cells in the testes to produce testosterone, leading to the physiological effects that benefit lean muscle mass, libido, improved insulin sensitivity, etc.
Testosterone is secreted in a pulsatile fashion (peaking between 200-400am) to avoid flooding the bloodstream and down-regulating testosterone receptors. That’s why your body uses negative feedback loops to control testosterone levels in the body; high serum testosterone inhibits GnRH from the hypothalamus and LH/FSH from the anterior pituitary via the hypothalamic-pituitary-gonadal (HPG) axis to manage optimal testosterone levels (see figure below).6
The hypothalmic-pituitary-gonadal axis and testosterone secretion.7
7 Reasons Why Your Testosterone Is Low
For most guys, the reason you struggle with low testosterone is because your normal production is being sabotaged. You don’t need to add more testosterone in the system, you need to remove the roadblocks and allow your brain and body the freedom to restore optimal levels. I’ve listed below seven common reasons and what you can do to reverse the trend.
High Belly Fat
If you’ve got significant abdominal adiposity, you don’t need a testosterone cream, you need to lose weight. Belly fat increases the activity of an enzyme called aromatase, which converts your precious testosterone to estrogen, a major root cause of low T for most men.
A whopping 80% of estradiol levels in the blood originates from the process of aromatization, which suppresses the HPG axis, thus down-regulating your natural testosterone production.7 To boost testosterone, lose the beer belly.
High belly fat is also strongly associated with chronic inflammation, another strike against you if you’re trying to boost testosterone levels. Excess abdominal adiposity is a surefire sign of systemic inflammation, meaning your body is “on fire” from head to toe.
Inflammation impairs healthy mitochondrial function, crucial for healthy testosterone production.8 Trim abdominal adiposity via diet and exercise to cool excessive inflammation and put the brakes on mitochondrial damage.
If you’re overweight and have significant belly fat, you’ll not only have increased aromatase activity and systemic inflammation impairing healthy testosterone output, but also chronically high blood sugar and insulin levels. Most often, this is due to the excessive intake of processed carbohydrates and sugar (and ultimately a major caloric excess). High insulin levels will shift testosterone output toward androstenedione, a much weaker form of testosterone, which takes up the “parking spots” on receptors your regular testosterone would occupy. As tempting as it can be to look for a quick-fix testosterone cream or gel solution, your best bet is to simply kick-start weight loss.
Try adopting a low-carb diet, adding in more slow-continuous and high-intensity interval training (HIIT), as well as total-body resistance training sessions centered around compound movements to achieve a caloric deficit, improve blood sugar and insulin balance, and cool chronic inflammation.
Lack of Sleep
It’s not just weight gain that can drag down your testosterone levels. Sleep is one of the most powerful, and often overlooked, weapons for increasing low T, and the best part is it’s completely free! The average person gets about six and half hours of sleep per night, and almost 30% of the population gets less than six every night.9 This is a major problem if you’re struggling with poor muscle mass, mood, libido or overall health.
As you age, your total sleep time is an independent predictor or your morning testosterone levels, rising in parallel with total sleep up to approximately eight hours per night.10 In short, the more sleep you get, the better your testosterone levels.
Even in healthy young men, lack of sleep is a major testosterone killer. The Journal of the American Medical Association recently found healthy men (average age of 24) who slept only five hours per night for one week experienced a 10-15% decline in testosterone.11 If you want to reboot your testosterone levels, aim for at least 7-9 hours per night, and add a few naps (30 or 90 minutes) to increase your total weekly sleep time. For performance-driven athletes, experts believe 70 hours of sleep per week should be your goal.
Our modern environment, with 24/7 connectivity and constantly being “on the go,” is at odds with our evolutionary drive to rest and recover. The cortisol stress hormone is derived from the same hormonal building blocks as testosterone, therefore if you’re burning the midnight oil and staying out late, you’ll likely be doing so at the expense of your precious testosterone.
Training is also a major stressor, and it’s well-established in the scientific literature that low testosterone is a common symptom of overtraining.12 Similar effects occur if you’re working long hours, getting too much screen time, or not enough sleep. Stress also worsens blood sugar and insulin control, predisposing you to all the weight gain, belly fat, chronic inflammation, and hyper-insulinemia mentioned above.
To offset stress, avoid excessive caffeine intake (especially before noon), reduce or eliminate alcohol in the evening, and find time (5-15 minutes) to perform breath work or disconnect from the daily grind of your workday.
Micronutrients like zinc and vitamin D are critical for testosterone production, and common deficiencies occur due to diets high in grains, blood sugar dysfunction, excess alcohol intake, and lack of sunshine.
But just because you add a supplement doesn’t mean you’ll boost your T levels. The research shows zinc supplementation can increase serum testosterone levels, but only in individuals who are deficient.13 Similarly, vitamin D is intimately involved in testosterone production, however blood levels above 40 ng/dl (150 nmol/L) are unlikely to provide any additional benefits.14 To sum up micronutrients, they can help nudge your testosterone in the right direction, however they aren’t the “big rocks” like maintaining your ideal weight, getting adequate sleep, and keeping stress under control.
Testosterone Medication Use
If you think you can fix your low T levels by simply slapping on a testosterone cream or gel, be warned, you’ll likely make the problem worse. Applying these gels topically on adipose (fat) tissue is an extremely poor method to raise testosterone levels, may accelerate aromatization, and can down-regulate your testosterone receptor activity, setting you up for problems in the future. Forget the pills and potions; address the six root causes above, and your libido and muscle mass will soon be on the rise.
Addressing the root causes of low testosterone may not be as “sexy” as the notion of taking an exotic supplement from depths of some distant jungle, or slapping on some testosterone cream and transforming into Superman. But the reality is the former will yield significant testosterone benefits, while the latter is unlikely to help. Get back to addressing why your T levels are low, and you’ll soon experience more lean muscle, improved libido, clearer thinking, and superior overall health.
1. Rao, Preethi M., Daniel M. Kelly, and T. Hugh Jones. “Testosterone and insulin resistance in the metabolic syndrome and T2DM in men.” Nature Reviews Endocrinology 9, no. 8 (2013): 479-493.
2. Kelly, Daniel M., and T. Hugh Jones. “Testosterone: a vascular hormone in health and disease.” Journal of Endocrinology 217, no. 3 (2013): R47-R71.
3. Chin, K-Y., S. Ima-Nirwana, Isa Naina Mohamed, Amilia Aminuddin, and W. Z. W. Ngah. “Total testosterone and sex hormone-binding globulin are significantly associated with metabolic syndrome in middle-aged and elderly men.” Experimental and Clinical Endocrinology & Diabetes 121, no. 07 (2013): 407-412.
4. Yeap, Bu B., Helman Alfonso, SA Paul Chubb, David J. Handelsman, Graeme J. Hankey, Osvaldo P. Almeida, Jonathan Golledge, Paul E. Norman, and Leon Flicker. “In older men an optimal plasma testosterone is associated with reduced all-cause mortality and higher dihydrotestosterone with reduced ischemic heart disease mortality, while estradiol levels do not predict mortality.” The Journal of Clinical Endocrinology & Metabolism 99, no. 1 (2013): E9-E18.
5. Kaufman, Jean M., and Alex Vermeulen. “The decline of androgen levels in elderly men and its clinical and therapeutic implications.” Endocrine Reviews 26, no. 6 (2005): 833-876.
6. Feldman, Henry A., Christopher Longcope, Carol A. Derby, Catherine B. Johannes, Andre B. Araujo, Andrea D. Coviello, William J. Bremner, and John B. McKinlay. “Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts male aging study.” The Journal of Clinical Endocrinology & Metabolism 87, no. 2 (2002): 589-598.
7. Ullah, M. Iftekhar, Daniel M. Riche, and Christian A. Koch. “Transdermal testosterone replacement therapy in men.” Drug Design, Development and Therapy 8 (2014): 101.
8. Kaufman, Jean M., and Alex Vermeulen. “The decline of androgen levels in elderly men and its clinical and therapeutic implications.” Endocrine Reviews 26, no. 6 (2005): 833-876.
9. Pasquali, Renato, Cinzia Macor, Valentina Vicennati, Francesca Rosaria De Iasio, Paolo Mesini, Stefano Boschi, Francesco Casimirri, and Roberto Vettor. “Effects of acute hyperinsulinemia on testosterone serum concentrations in adult obese and normal-weight men.” Metabolism 46, no. 5 (1997): 526-529.
10. Penev, Plamen D. “Association between sleep and morning testosterone levels in older men.” Sleep 30, no. 4 (2007): 427.
11. Leproult, Rachel, and Eve Van Cauter. “Effect of 1 week of sleep restriction on testosterone levels in young healthy men.” JAMA 305, no. 21 (2011): 2173-2174.
12. Kreher, Jeffrey B., and Jennifer B. Schwartz. “Overtraining syndrome: a practical guide.” Sports Health 4, no. 2 (2012): 128-138.
13. Prasad, Ananda S., Chris S. Mantzoros, Frances WJ Beck, Joseph W. Hess, and George J. Brewer. “Zinc status and serum testosterone levels of healthy adults.” Nutrition 12, no. 5 (1996): 344-348.
14. Pilz, S., S. Frisch, H. Koertke, J. Kuhn, J. Dreier, B. Obermayer-Pietsch, E. Wehr, and A. Zittermann. “Effect of vitamin D supplementation on testosterone levels in men.” Hormone and Metabolic Research 43, no. 03 (2011): 223-225.