Reviewed by Denise Asafu-Adjei, M.D., MPH
A few years back, PN co-founder John Berardi, PhD, posted a shirtless photo of himself on his 47th birthday.
He called it his “anti-regress pic” and thanked 30 years of squats, deadlifts, presses, and chin-ups—among other exercises—for his chiseled six-pack, pumped chest, and bulging biceps.
The question many commenters posed:
“Are you on testosterone?”
Dr. Berardi explained in a follow-up post that while he wasn’t against testosterone replacement therapy (TRT) for people who needed it, he himself was not on this therapy, and his testosterone levels were boringly “normal.” He also offered some thought-provoking ideas about testosterone and aging.
- The mainstream opinion seems to be that declining testosterone is a harbinger of aging, frailty, and impotence—not to mention a threat to masculinity.
- Increasing numbers of middle-aged men are ditching traditional medical checkups for men’s-focused telehealth clinics that specialize in testosterone enhancement.1
- Reddit communities have popped up solely to obsess over neuroscientist Andrew Huberman’s supplement recommendations for optimizing testosterone.
- Media outlets pump out story after story about “testosterone boosting” foods to eat and “testosterone lowering” foods to avoid.
Whether you’re a coach who fields the “How do I optimize testosterone?” question from clients—or just a regular dude hoping to age well—it’s easy to feel overwhelmed and confused by the conflicting information.
Are declining testosterone levels normal?
Do testosterone-boosting supplement regimens actually work?
Who benefits from testosterone therapy—and who doesn’t?
In this story, we’ll explore those questions and more.
What is testosterone?
Secreted by the testes, testosterone is the sex hormone responsible for male sexual characteristics such as big muscles, deep voices, and hairy chests. It’s a chemical messenger that plays a key role in various processes throughout the body, including sperm production and bone density.
(In women, who also need testosterone to keep various processes humming, testosterone is secreted by the ovaries and adrenal glands. Their bodies just make much less of it; about 10 to 20 times less than men.)
Possibly because of its relationship with muscle growth and sex drive, a lot of cisgender men think of testosterone in binary terms, with lower testosterone being bad and higher testosterone being good.
However, it’s more accurate to think of the relationship between testosterone and health as a continuum that goes from too low (problematic) to too high (also problematic), with the healthy range falling between the two extremes, says Denise Asafu-Adjei, MD, MPH, urologist, men’s health expert, and assistant professor of urology at Loyola University Chicago-Stritch School of Medicine.
As the chart below shows, the dangers of extremely low testosterone are similar to the risks of extremely high amounts (typically only achievable with the use of anabolic steroids).
| Problems associated with extremely LOW testosterone | Problems associated with extremely HIGH testosterone |
|---|---|
|
|
Low testosterone vs. lower testosterone
Testosterone levels naturally ebb with age, with most men losing about 1 to 2 percent annually starting around age 40. By age 75, most men have 30 percent less of the hormone than they did at age 25.2
(Fun fact: Between ages 25 and 80, men can expect their testicles to shrink 15 percent.3)
However, age-related drops in testosterone are not the same thing as “low testosterone.”
Hypogonadism is the medical term for low testosterone levels, and it affects about 35 percent of men older than 45 and 30 to 50 percent of men who have obesity or type 2 diabetes, according to the Endocrine Society, one of the professional public health organizations that sets hypogonadism treatment guidelines.
Not only can overly low testosterone make you feel fatigued and do a serious number on your sex drive, but it can also harm your bone and cardiovascular health, says Dr. Asafu-Adjei.
“You need testosterone for good bone strength,” says Dr. Asafu-Adjei. “As you get older, you’re already dealing with weaker bones, so having lowered testosterone isn’t going to help.”
Alternatively, bringing levels up to normal seems to offer cardiovascular benefits, she says. (The big caveat here is up to normal—not far above it.)
The importance of referring out
What if you or your client have most of the hallmark symptoms of hypogonadism but still have blood levels of testosterone in the normal range?
“Many men over 30 who feel down or low energy will now automatically blame their testosterone,” says Dr. Asafu-Adjei. “Their symptoms might be related to testosterone, but they also could be related to not sleeping, stress, or some other factor.”
That’s why seeing a healthcare professional specializing in men’s health and testosterone management is so important.
Such a physician can screen you or your client for dozens of other problems (like stress and poor sleep) and conditions (like diabetes, obesity, or sleep apnea) that either mimic the symptoms of hypogonadism or interfere with the production or signaling of testosterone.
In other words, supplemental testosterone is the answer for some men with symptoms of hypogonadism, but not all of them. An extensive workup is required.
“There are overlapping symptoms with low testosterone as well as a lot of nuances around hormone treatment,” says Dr. Asafu-Adjei.
“For example, outside of your total testosterone, we also look at your testosterone-to-estrogen ratio and other related hormones. That’s why it’s so important to go to someone who knows what they’re doing. They’ll take a deeper dive to figure out the root of the problem.”
So, if you specialize in coaching middle-aged and older men, get a urologist or endocrinologist in your referral network.
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Testosterone and aggression
Many people assume that, in high amounts, testosterone turns men into pushy, road-rage-fueled jerks. However, the association between the hormone and behavior is much more complex.4
As it turns out, both too much and too little testosterone can lead to irritability.
In addition, the link between testosterone and aggression depends a lot on someone’s personality, upbringing, context, social norms, and more.
For example, in one experiment, researchers asked forty young men to play a video game that involved accepting and rejecting offers from a proposer. If someone deemed the proposal too low, they could reject the offer and punish the person for making such a substandard ask. Alternatively, if they considered the offer beneficial, they could accept it as well as reward the person.5
Researchers injected some of the men with testosterone as they played the game.
As expected, players treated with the hormone were more likely to punish proposers, especially if they considered the offer unfair. However, if they perceived the offer as fair, they rewarded the proposer more generously.
The increased testosterone amplified aggression, but also generosity.
Some researchers refer to this phenomenon as “the male warrior hypothesis,” which holds that testosterone may function to help some men protect and cooperate with their “in group” (such as their family, friends, and coworkers) while simultaneously punishing anyone seen as an outsider.6
7 evidence-based ways to optimize testosterone… naturally
On the Internet, if you look for ways to boost testosterone through lifestyle, you’ll quickly become inundated with supplement recommendations and lists of T-boosting and T-harming foods.
However, research-supported ways to optimize testosterone generally center on the fundamental dietary and lifestyle measures you’ve long heard are good for you.
They include the following:
Testosterone optimizer #1: Make sure you’re eating enough.
Your body prioritizes thinking (your brain) and movement (your muscles) above sex (your reproductive organs).
Think about it this way: If there was a famine, the last thing you’d need is another mouth to feed.
So, when you chronically burn more calories than you consume, hormone levels generally drop. (This is true in both men and women.)
“A lot of men in their 20s and 30s come to me about their low testosterone levels and their low testosterone symptoms,” says Dr. Berardi. “These are mostly guys who prioritize exercise. They work out a lot and watch what they eat. In other words, they are men experiencing mid- to long-term negative energy balance.”
Dr. Berardi’s advice is often not what men expect.
If their eating and exercise routines suggest they’re in a chronic negative energy situation, he simply recommends they eat an extra healthy snack or two a day.
“In situations like this, adding a couple hundred extra calories of high-quality protein and carbohydrate often fixes everything,” he says.
Those added calories could come from a couple scoops of whey protein mixed in milk with a nut butter and banana sandwich on the side, he says.
Another favorite snack of Dr. Berardi’s: A bowl of steel-cut oats with protein powder, cacao powder, dates, raw nuts, and nut butter.
Keep in mind: Eating too much (and gaining fat) can also affect testosterone, as we’ll cover soon. Use our FREE nutrition calculator to ensure you’re consuming the right amount of calories and nutrients to support hormone production.
Testosterone optimizer #2: Prioritize sleep.
Testosterone production has its own circadian rhythm: It’s higher in the morning and lower at the end of the day.
As you sleep, levels rise again, peaking during your first segment of rapid eye movement. This may explain why various sleep disorders—including sleep apnea—are associated with testosterone deficiency.7
A handful of small studies have looked at what happens to hormone levels when men skimp on sleep.8 In one of these studies, participants slept just five hours a night for eight days, resulting in a 10 to 15 percent drop in daytime testosterone levels. 9
The right amount of sleep varies from one person to another. However, if you routinely get fewer than seven hours and wake feeling exhausted, it’s a good bet you’re not getting enough. If you wake unrefreshed or struggle to sleep soundly, our 14-day sleep plan can help.
Testosterone optimizer #3: Maintain healthy body fat levels.
Body fat secretes aromatase, an enzyme that can convert some testosterone into estrogen.
According to some research, men categorized as overweight or obese tend to have slightly higher levels of estrogen, as well as the stress hormone cortisol. 10 11
More research is needed to know whether these slightly higher estrogen levels are enough to contribute to hypogonadism.
In the meantime, however, a healthy body composition is vital for overall good health and may also help to optimize testosterone.
Keep in mind, as we said above, that too little body fat can also negatively affect testosterone levels. To ensure your body fat levels are in the optimal zone, use our FREE body fat calculator.
Testosterone optimizer #4: Get moving.
Regular exercise is associated with elevations in testosterone. It can also help you sleep more restfully and keep body fat in check.
Resistance training offers more of a testosterone boost than endurance exercise. (Two to three sessions a week is a great benchmark.)
However, endurance exercise can also help, providing you exercise at the right intensity, finds research. (That’s 30 minutes of rigorous activity, four to five times a week.12)
Overtraining without enough recovery can lead to the opposite effect though, potentially causing gains to plateau and suppressing testosterone.13
(See our FREE exercise library for 400+ expert how-to videos and a 14-day at-home workout program.)
Testosterone optimizer #5: Consume a well-rounded, healthy diet.
In addition to helping you avoid nutrient deficiencies that can drive down testosterone levels, a healthy diet protects your blood vessels.
That’s crucial for getting erections.
A study of 21,469 men found that those who consumed foods consistent with the Mediterranean diet had a lower risk of developing erectile dysfunction over ten years compared to men who didn’t follow the diet.14
“Mediterranean diets are also known to promote heart health,” says Dr. Asafu-Adjei.
The Mediterranean diet emphasizes fruit, vegetables, whole grains, nuts and legumes, and healthy fats from foods like olive oil, eggs, and fatty fish. It de-emphasizes red and processed meat, sugar-sweetened beverages, and sodium.
However, eating patterns that center on minimally processed whole foods likely offer the same benefits.
Many fruits, veggies, and other minimally processed whole foods are rich sources of flavonoids, a plant chemical that helps to improve blood flow and testosterone production.
(This visual eating guide can help you choose the best foods for your body.)
Testosterone optimizer #6: Avoid chronic emotional stress.
When you’re under stress, your body produces cortisol and other hormones that prepare you to fight, flee, or freeze. As these stress hormones flood your body, they suppress the production of reproductive hormones like testosterone.15
This high-cortisol, low-testosterone phenomenon is a likely consequence of millions of years of evolution.
Early humans who were more interested in mating than fleeing from sharp-clawed wild animals didn’t usually live long enough to pass their genes to the next generation.
However, not all short-term stressors dampen testosterone. Some can raise it temporarily, including exam stress or exercise.16
So, aim for the stress sweet spot where you feel energized and engaged with life but not so busy and harried that you have no time to relax, sleep, or enjoy life.
(Learn more: How to tell the difference between good stress and bad stress.)
Testosterone optimizer #7: Prevent zinc deficiency.
As a certified health coach, it’s out of your scope of practice to recommend supplements to treat a condition like hypogonadism.
In addition, the boost someone might get from a supplement pales in comparison to the six pieces of advice above, or to testosterone therapy.
With that important caveat out of the way…
There is a correlation between low zinc intake and low testosterone levels.17 18
However, to benefit from supplementation, someone must truly be deficient in the mineral. Simply topping off someone’s already adequate zinc stores likely won’t lead to a testosterone boost, and may even cause harm.
Checking for and treating a mineral deficiency requires the expertise of someone trained in medical nutrition therapy. If you lack this training, encourage clients with low testosterone to talk to their healthcare professionals about whether a zinc supplement might help.
Use the Deep Health lens
Let’s circle back to Dr. Berardi’s hypothesis, first mentioned at the beginning of this story:
Some evolutionary biologists have indeed theorized that men evolved to have higher testosterone levels when they’re younger (to encourage mating) and lower levels when they’re older (to encourage parenting).19
However, this is more of a theory than a certainty.
What we can say with certainty is this: There’s no one-size-fits-all protocol for healthy testosterone levels.
When testosterone drops after middle age, some men feel lousy.
Even when they do everything right in the lifestyle department—exercising, eating a healthy diet, sleeping enough, and so on—they’re unable to raise testosterone into the normal range. For these men, a healthcare professional, thorough evaluation, and, if warranted, testosterone therapy can be life-changing.
At the same time, plenty of other men continue to thrive well into (and past!) middle age.
Sure, they may be unable to pack on muscle like they used to. But, if they’re paying attention, suggests Dr. Berardi, they might notice other pluses. Maybe they’re more patient, nurturing, and empathetic, for example.
“Don’t get me wrong. I’d be very unhappy with an inappropriate or clinically significant lowering of my hormone levels,” says Dr. Berardi. “However, if I can stay in the normal range and symptom-free with good lifestyle practices, I don’t think I have too much to worry about.”
Dr. Berardi recently turned 50.
“I’m at this stage where I see an interesting fork in the road,” he said.
“Will I gracefully accept aging and see this as a new season—or will I fight against it? I could color my hair, do hair transplants, top up my T levels, and get Botox injections. Or I could accept that there will be some eventual decline and ask, ‘What am I getting in return?’”
References
Click here to view the information sources referenced in this article.
- Hudnall MT, Ambulkar SS, Lai JD, Pham MN, Fantus RJ, Keeter MK, et al. Characteristics of men who use direct-to-consumer men’s health telemedicine services. Int J Impot Res. 2023 Dec;35(8):753–7.
- Decaroli MC, Rochira V. Aging and sex hormones in males. Virulence. 2017 Jul 4;8(5):545–70.
- Barone B, Napolitano L, Abate M, Cirillo L, Reccia P, Passaro F, et al. The Role of Testosterone in the Elderly: What Do We Know? Int J Mol Sci [Internet]. 2022 Mar 24;23(7).
- Geniole SN, Bird BM, McVittie JS, Purcell RB, Archer J, Carré JM. Is testosterone linked to human aggression? A meta-analytic examination of the relationship between baseline, dynamic, and manipulated testosterone on human aggression. Horm Behav. 2020 Jul;123:104644.
- Dreher JC, Dunne S, Pazderska A, Frodl T, Nolan JJ, O’Doherty JP. Testosterone causes both prosocial and antisocial status-enhancing behaviors in human males. Proc Natl Acad Sci U S A. 2016 Oct 11;113(41):11633–8.
- Muñoz-Reyes JA, Polo P, Valenzuela N, Pavez P, Ramírez-Herrera O, Figueroa O, et al. The Male Warrior Hypothesis: Testosterone-related Cooperation and Aggression in the Context of Intergroup Conflict. Sci Rep. 2020 Jan 15;10(1):375.
- Agrawal P, Singh SM, Able C, Kohn TP, Herati AS. Sleep disorders are associated with testosterone deficiency and erectile dysfunction—a U.S. claims database analysis. Int J Impot Res. 2022 Dec 6;36(1):78–82.
- Su L, Zhang SZ, Zhu J, Wu J, Jiao YZ. Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis. Sleep Med. 2021 Dec;88:267–73.
- Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011 Jun 1;305(21):2173–4.
- Stárka L, Hill M, Pospíšilová H, Dušková M. Estradiol, obesity and hypogonadism. Physiol Res. 2020 Sep 30;69(Suppl 2):S273–8.
- Wrzosek M, Woźniak J, Włodarek D. The causes of adverse changes of testosterone levels in men. Expert Rev Endocrinol Metab. 2020 Sep;15(5):355–62.
- Riachy R, McKinney K, Tuvdendorj DR. Various Factors May Modulate the Effect of Exercise on Testosterone Levels in Men. J Funct Morphol Kinesiol [Internet]. 2020 Nov 7;5(4).
- Hackney AC. Hypogonadism in Exercising Males: Dysfunction or Adaptive-Regulatory Adjustment? Front Endocrinol. 2020 Jan 31;11:11.
- Bauer SR, Breyer BN, Stampfer MJ, Rimm EB, Giovannucci EL, Kenfield SA. Association of Diet With Erectile Dysfunction Among Men in the Health Professionals Follow-up Study. JAMA Netw Open. 2020 Nov 2;3(11):e2021701.
- Khan SU, Jannat S, Shaukat H, Unab S, Tanzeela, Akram M, et al. Stress Induced Cortisol Release Depresses The Secretion of Testosterone in Patients With Type 2 Diabetes Mellitus. Clin Med Insights Endocrinol Diabetes. 2023 Jan 3;16:11795514221145841.
- Afrisham R, Sadegh-Nejadi S, SoliemaniFar O, Kooti W, Ashtary-Larky D, Alamiri F, et al. Salivary Testosterone Levels Under Psychological Stress and Its Relationship with Rumination and Five Personality Traits in Medical Students. Psychiatry Investig. 2016 Nov;13(6):637–43.
- Te L, Liu J, Ma J, Wang S. Correlation between serum zinc and testosterone: A systematic review. J Trace Elem Med Biol. 2023 Mar;76:127124.
- Hunt CD, Johnson PE, Herbel J, Mullen LK. Effects of dietary zinc depletion on seminal volume and zinc loss, serum testosterone concentrations, and sperm morphology in young men. Am J Clin Nutr. 1992 Jul;56(1):148–57.
- Gray PB. The descent of a man’s testosterone. Proc Natl Acad Sci U S A. 2011 Sep 27;108(39):16141–2.
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