“Across the population, men today have less testosterone compared to men of the same age a generation ago. Asking why requires untangling a complex web of social, environmental, and behavioral factors that are dismantling age-old ideas about masculinity and triggering real anxiety over changing gender roles.”

— Neil Howe

Key Takeaways

Hormones play a pivotal role in our health and wellbeing, and they are the driving force behind mood, energy levels, and decision making.
Levels of testosterone, the most important hormone for body composition, mood, and overall health, have plummeted since the 1980’s and show no signs of slowing down.
The 3 main aspects of life that play the most significant role in this widespread reduction in testosterone levels: lifestyle, fitness, and exposure to environmental toxins.
Managing stress, improving our diets, prioritizing quality sleep, exercising regularly and reducing exposure to hormone disrupting chemicals are the most important steps we can take to support hormone production.
The battle against testosterone decline is a tall order, but we’re not doomed to low testosterone for the rest of our lives. By knowing the causes of low testosterone, and the most effective ways to overcome them, we can naturally boost our testosterone levels and be more muscular, healthier, and happier.

Background

Do you understand the driving force behind your mood, energy levels, and decision making? You may believe that you're in control - that you’re cranky because you skipped lunch, or tired because you stayed up late binge watching Schitt’s Creek. On one level, you’d be correct. You may be able to accurately identify the chain of events that led to your emotions, but I bet you don’t understand why exactly you feel that way. The answer? Hormones.

Hormones, chemical messengers in the body, run the show. You’re simply an actor. Sure, you may be the star - the Dwayne ‘The Rock’ Johnson of your own movie, if you will - but hormones are the writers, directors, and producers. Hormones impact every single decision you make. What you eat, how you carry yourself, who you decide to befriend, when you go to bed (or who you go to bed with) are all decided by hormones. For instance, the following hormones are well known for the especially important influence they have on our behavior:

Ghrelin - makes us feel hungry
Leptin - makes us feel full
Oxytocin - affects how trusting we are and who we decide to be friendly with
Dopamine - makes us happy and increases motivation
Serotonin - makes us happy
Cortisol - makes us sad and alert
Estrogen - improves mood, increases sex drive, affects body composition
Testosterone - improves mood, increases sex drive, affects body composition, increases aggression

These generalizations are extremely broad and incomplete. Endocrinology (the study of hormones) is incredibly complex, and I don’t intend to, nor could I, paint you a complete picture of every effect of each hormone. The key takeaway is that, due to the litany of effects that they have on every aspect of life, having suboptimal hormone levels can have serious consequences for your health and wellbeing.

Why Testosterone is Important

This brings us to today’s question, “Why are our grandpas manlier than us?” The answer, quite simply, is that average levels of testosterone across the country have utterly plummeted since the 1980’s, resulting in lower sexual desire, less muscle mass, and worsened mood. (Ladies, you may want to stick around - this article is a discussion of how levels of one hormone have changed on a population level over the past 50 years, and the primary points apply perfectly well to changes in other hormones (i.e. estrogen) that may pertain more directly to you).

What comes to mind when you read the words “manly man?”* If you’re anything like me, a kid that was raised on professional wrestling and football, I bet you picture broad shoulders, a bellowing voice, and thick facial hair. The hormone responsible for all of these classic masculine traits is, you guessed it, testosterone! While testosterone may not directly transform us into the Hulk, it sets the physiological stage for:

More muscle
Less fat
Increased bone density
Deeper voice
More energy
Improved mood
More body hair
Higher sex drive
Better sperm production

As you can see, having adequate levels of testosterone is conducive to leading a happy and healthy life. On the other hand, low levels of testosterone can lead to:

Less muscle
More fat
Decreased bone density
Less energy
Worsened mood and increased risk of depression
Loss of body hair
Lower sex drive
Less sperm production and/or impotence (1)

It is important to note that in regard to testosterone, more is not always better! It is virtually impossible to naturally produce excessive testosterone levels, but an abnormally high testosterone level created either artificially (i.e. after using anabolic drugs) or in certain disease states has its own array of negative effects. In general, within a normal physiologic range, higher testosterone is usually better than lower.

*Disclaimer - the last thing I want to do is perpetuate harmful gender stereotypes or toxic masculinity. My intention is to consider the stereotype of masculinity as portrayed in the media and everyday life and discuss the effect of testosterone on those common traits.

Your Grandpa Had Higher Levels of Testosterone Than You

Now that we know what testosterone is and why it’s important, let’s dive into the specifics of its decline in men across United States. Researchers have found that from 1980 to the early 2000’s, testosterone levels in men have decreased by about 1% every year (2). Even more concerning, in the last 20 years the average testosterone level has dropped even lower, from 605 to 450 ng/dL (a 27% decrease)! (3). In other words, a 22 year old today has the testosterone levels of a 67 year old man (the age of your grandpa, perhaps?) in 2000 (4). Unsurprisingly, the fertility rate over the past 20 years has steadily declined as well (5).

Perhaps the most disappointing for those of you that pride yourselves on your fitness, this 2016 study showed that the average 20-34 year old man today has nearly a 20lb weaker grip strength than a man of the same age in 1985 (6). The problem isn’t isolated to the United States, either. This study in Danish men found similar troubling trends (7). This significant decline in average testosterone shows no signs of slowing down, and the effects are absolutely abysmal.

The average fertility rate has declined along with average testosterone levels (8).

The Cause of the Decline and How to Optimize Your Hormone Production

Though the cause is multifaceted, there are 3 main aspects of life that play the most significant role in this widespread reduction in testosterone levels: lifestyle, fitness, and exposure to environmental toxins. More specifically, the most important steps we can take to support hormone production and maintain healthy testosterone levels include managing stress, improving our diets, prioritizing quality sleep, exercising regularly and reducing exposure to hormone disrupting chemicals.

Lifestyle

Stress

Effect on Testosterone
“To be totally without stress is to be dead” - Hans Selye. In contrast to popular belief not all stress is harmful. Acute stress helped our ancestors find food and flee from lions - it is performance enhancing, healthy, and essential to your survival. Chronic stress, on the other hand, wreaks havoc on testosterone levels and is, quite frankly, killing us. Today, we’re:
- Stressed when our alarm clock goes off
- Stressed when that Yellow Hummer cuts us off on the way to work
- Stressed at work
- Stressed about what to eat for lunch
- Stressed when that Yellow Hummer cuts us off on the way home
- Stressed when your partner burns the casserole
- Stressed when you can’t fall asleep because you’re so stressed
- Every. Single. Day.

During periods of stress, cortisol (the “stress” hormone) rises, and catabolic (“break down”) hormones increase while anabolic (“build up”) hormones, i.e. testosterone, decrease. We have a seesaw relationship - as cortisol goes up, testosterone goes down (9, 10, 11). It makes sense that when evading death is a present concern, your body will prioritize survival over everything else, reproduction, muscle growth, and happiness included. This testosterone reduction is observed after excessive physical stress, such as overtraining (12, 13, 14), as well as psychological stress (15, 16, 17).

How to Fix It
- The answer to reducing stress is simple - stop being so stressed! Just quit your job, throw on your favorite tie dyed top and flower headband, and hum Kumbaya around a fire all day. Alternatively, here are some other effective stress reducing habits:
  - Deep breathing - I know it may sound woo-woo, but taking a few deep breaths really does wonders for reducing stress. Next time you’re feeling stressed, try performing “box breathing” - breathe in for 4, hold for 4, breathe out for 4, hold for 4, and repeat 4 times.
  - Exercise - taking part in an acute stressor, such as exercise, can actually reduce chronically high levels of stress. Just be sure to not to overdo it, or else it can further drive up stress levels.
  - Quality sleep - establishing a pre-bed routine and getting quality sleep is the best way to refresh and recharge after a stressful day.
  - Practice mindfulness - meditation has been shown to drastically reduce stress levels (18). Not your thing? Try taking just 1-2 minutes per day to focus entirely on the present moment. As they say, depression is caused by living in the past and anxiety is caused by living in the future. Sharpening your focus on the present moment may reduce your stress and help you feel more at ease.

“Essentially, we humans live well enough and long enough, and are smart enough, to generate all sorts of stressful events purely in our heads.”

— Robert Sapolsky

2. Diet

Effect on Testosterone
You may already know from hormones directly associated with food intake, such as insulin, ghrelin, and leptin, that what we eat has a direct effect on our hormone levels (19). As many of our hormones have cascading effects on other hormones, it follows that what we eat, how much we eat, and even how we eat can directly impact testosterone.

What we eat- This 2020 study of nearly 3000 men found those that consumed the “Western Diet”, an eating pattern associated with high intakes of added sugar, unhealthy fats, and heavily processed foods had a lower sperm count, likely as a result of lower testosterone levels, than those that consumed more fruits, vegetables, and other minimally processed foods (20). Other studies have found similar associations between poor diet and low testosterone levels (21, 22). We also know that certain deficiencies, such as vitamin D, magnesium, zinc, and dietary fat in general, are linked to low testosterone (23, 24, 25, 26).

How much we eat- When it comes to testosterone, the amount we eat is even more important than what we eat. In short, both eating too much and eating too little prevents optimal hormone production. Due to the downstream effects of insulin resistance on testosterone, obesity is a major worldwide cause of low testosterone levels (27, 28, 29).

As rates of obesity have continued to increase over the past 40 years, an inverse relationship between obesity and testosterone levels has emerged. It is not unlikely that this soaring rate of obesity is one of the primary culprits to blame for our testosterone troubles (30, 31).

On the other end of the spectrum, we see reductions in sex hormones in those that have been dieting for an extended period of time, as well as in women with athletic amenorrhea, the loss of menstrual periods in endurance athletes. It’s the same stressful story - extreme weight loss or high amounts of activity impart a strong stressor on the body, telling it, “hey, we’re DYING over here. Let’s pause reproduction for a bit.” Reproduction is important - without it the human race would perish and there would be nobody left to stop apes from taking over the world. But, again, the body will put a hold on every other function if the most important priority, our survival, is threatened (32).

How we eat- How we eat is important because of stress. Do you hurriedly scarf down your lunch over the kitchen sink in between meetings? Or do you sit down, relax, and eat mindfully? By eating mindfully instead of stressfully, we can improve our digestion and metabolic response to the meal, indirectly supporting optimal testosterone production.

How to Fix It

What We Eat- To support optimal hormone production, you can’t go wrong with consuming a diet full of fruits and vegetables, protein, healthy fats, fiber, and, overall, one that consists primarily of minimally processed foods.
How Much We Eat- Eat in a way that allows you to attain/maintain a healthy body composition. If you’re severely overweight or obese, consuming fewer calories and losing weight will result in improved testosterone levels. On the flip side, if you’re underweight or have been dieting for an extended period of time, consuming more calories and increasing your bodyweight will support optimal hormone production.
How We Eat- Take a few mindful, deep breaths before each meal. Sit down at a table with minimal distractions, eat slowly, and chew each bite thoroughly. Remember that eating and having access to food is a privilege (33).

3. Sleep

Effect on Testosterone
Poor quality sleep has been linked to significantly reduced testosterone levels in men. I mentioned in “8 Reasons to Sleep Before You’re Dead” that in just one week of sleep deprivation (5 hours sleep/night), testosterone levels plummet by 10-15% in healthy young men, and other studies have reported similar findings (34, 35, 36). Chronic stress only compounds this issue and creates a vicious cycle: stress is a major cause of poor sleep, while poor quality sleep increases stress levels, and both reduce testosterone (37).

How to Fix It

Tips for improving sleep quality include:

Make time for a 7-9 hour sleep opportunity each night

Establish a pre-bed routine
Before bed, avoid electronics, wear blue light blocking glasses, or download an app such as “f.lux” that reduces that amount of blue light emitted from your device.
Cut off caffeine early in the afternoon, at the latest. Caffeine has a half life of around 5 hours, meaning if you consume a Starbucks coffee at 4pm, half of the caffeine will still be floating in your bloodstream at 9pm.
Keep your room dark, cold (around 68 deg F or lower), and quiet
Limit large meals and alcohol before bed

Fitness

Lack of exercise

Effect on Testosterone
Exercise increases testosterone both directly through acute hormonal effects following resistance training as well as indirectly through the maintenance of a healthy body composition. It has been shown that testosterone and growth hormone levels rise for up to 1 hour after performing a resistance training session (38, 39, 40).
The research is mixed on the significance of this acute spike, but consistent exercise over the long term has been shown to increase testosterone levels. This study in untrained men found that one year of exercise improved male sex hormone levels by 14.5% and this study showed that, in general, men that exercise have more testosterone than their more sedentary counterparts (41, 42). Finally, this 2016 study in overweight men found that regular exercise had a stronger testosterone boosting effect than losing weight! (43). Regardless of the acute effects or specific long term mechanisms, it is clear that more exercise, more muscle, and better overall health creates an optimal biological environment for testosterone production (44).
How to Fix It
Implement a regular exercise routine. Resistance training has been shown to have the most potent testosterone improving effect but any exercise, if it helps you maintain a healthy bodyweight, will support hormone production. Find the type of exercise you enjoy in the amount you can handle, and do it consistently!
2. Increased Sedentary Time
- Effect on Testosterone
  More time sitting at your desk or lounging on your couch → less exercise, less muscle, higher bodyweight, higher stress→ lower testosterone levels.
- How to Fix It
  When working at your desk, set reminders on your phone to get up and move around every hour or so. Go for frequent, short walks in the morning (this will also improve sleep quality), after meals, or before you lock up at night.

“Rome wasn’t built in a day, but they were laying bricks every hour.”

— James Clear

Environmental Toxins

Endocrine Disruptors

Effect on Testosterone
Right up there with rising rates of obesity, exposure to environmental toxins is the most concerning, and certainly the most insidious, testosterone reducing change we’ve experienced on a population level (45, 46). As environmental pollution is not my area of expertise, I’m going to give you a 30,000 foot view. Endocrine disrupting (i.e. hormone altering) compounds that have been shown to reduce levels of male sex hormones include:
- BPA - linked to cancer, obesity, and early puberty. Up to 93% of Americans may have BPA in their bodies.
- Phthalates and other additives in plastics - may cause death of testicular cells. Linked to lower sperm count/poor sperm quality, birth defects, obesity, and thyroid dysfunction (47, 48).
- Glyphosate - may cause endocrine disruption and oxidative stress, linked to cancer, as well as liver and kideny disease (49, 50).
- PCB - linked to cancer, developmental defects, and reduced immune function (51, 52, 53).
- Dioxin - may disrupt normal sex hormone function. May lower sperm quality and decrease immune function (54).
- Flame Retardants - chemicals in flame retardants imitate thyroid hormone and may lead to lower IQ (55).
- Arsenic - linked to skin, bladder, and lung cancer. May disrupt metabolic hormones that play role in weight gain, immune function, insulin resistance, and high blood pressure (56).
In addition to these endocrine disruptors, perchlorate, atrazine (the one that turns male frogs into female frogs) , lead, mercury, PFC’s, and glycol ethers, among many others, raise cause for concern (57, 58).

How to Fix It
Solokas Focus audience, I’m always going to be honest with you. When I don’t know something, and it happens often, I’m going to admit it! I don’t know which chemicals are the most harmful, the levels at which they become a problem, or the most effective ways to reduce exposure. Instead of guessing and risk leading you astray, I’m going to refer you to some reputable resources:
- This 15 page guide on the most common endocrine disruptors and how to avoid them, from the Environmental Working Group (59).
- This list of tips from the NRDC (60).
- And this short list from the Endocrine Society (61).
Some highlights (62):
- BPA - avoid canned foods that aren’t labeled “BPA free”, avoid handling receipts (often coated with BPA), choose “BPA free” tupperware.
- Phthalates and other additives in plastics - avoid using plastic containers/toys that contain BPA. Avoid products that contain “fragrance” in the ingredients, as it may mean the product contains phthalates. Choose phthalate free personal care products.
- Glyphosate - Choose organic fruits, vegetables, and grains, especially if they are included in the “dirty dozen”, a list of produce that is traditionally high in glyphosate (63). Consume more sulfur rich foods such as eggs, onion, and garlic, as sulfur plays an important role in the body’s detoxification process (64, 65).
- PCB - mainly found in fish. Instead of frying fish, barbecue, broil, or bake on a rack that allows the fat to drip off. Wash fruits and vegetables (especially if they’re not organic) (66).
- Dioxin - usually found in meat and dairy products.
- Flame Retardants - urge Congress to pass stricter chemical regulation laws. Using a vacuum with a HEPA filter and keeping your living space free of dust may reduce exposure.
- Arsenic - avoid foods high in arsenic and use an arsenic reducing water filter.

Wrap Up

The battle against testosterone decline is a tall order. Society has evolved to put us in positions of high stress, made it more convenient than ever to consume an unhealthy diet, and increased the necessity of surviving with poor sleep quality. We as a country have also become more sedentary than ever, with jobs that chain us to our desks and leave little time to take a deep breath, let alone make time to workout. Finally, our environment is employing an all-out chemical assault against our hormonal system, with everything from our plastic bottles to our shampoo acting as endocrine disrupting kamikazes. The odds are stacked in the wrong direction, but I’m not going to bet against us.

On the bright side, identifying the cause of the problem brings us one step closer to the solution. We’re not doomed to low testosterone for the rest of our lives and, fortunately, the power is in our hands! Now that we know the causes of low testosterone, and the most effective ways to overcome them, we can take the steps to naturally boost our testosterone levels and be more muscular, healthier, and happier. Take that Grandpa.