A guy in his early 40s walks into his doctor’s office. He’s tired all the time. He’s putting on belly fat he can’t lose. His motivation is gone. He asks to get his testosterone checked.
The lab comes back at 320. His doctor says, “You’re totally fine.”
He leaves with no answers.
That number, 320, falls inside the standard reference range. Technically normal. But he could double it and feel like a different person.
The Reference Range Problem
The standard lab range for total testosterone in men is 300 to 1,000. That’s a massive spread. A man sitting at 310 and a man sitting at 950 both get the same label: normal.
Where do those ranges come from? Population averages. Millions of blood draws collected over years, from all ages, all health statuses. Sick people are in that data set. Sedentary people. Men already in hormonal decline. The range reflects what’s common, not what’s good.
Functional medicine draws a different line. The optimal range for a man, at any age, is roughly 700 to 1,000 total testosterone. That’s the range where men tend to feel strong, sleep well, think clearly, and maintain healthy body composition.
So when a 45-year-old shows up at 320 and his doctor shrugs, the doctor isn’t wrong by conventional standards. He’s just not asking the right question. “Is it normal?” is the wrong question. “Is it optimal?” is the one that matters.
And here’s a number most men never hear: after age 30 to 35, testosterone drops by about 1 to 2 percent per year. It’s a slow bleed. By the time symptoms stack up enough to go see a doctor, a man could be decades into a steady decline that no one flagged.
What “Suboptimal” Actually Feels Like
Low or suboptimal testosterone doesn’t announce itself with flashing lights. It shows up as things you write off. Things you blame on age, on being busy, on not sleeping enough.
Fatigue that sleep doesn’t fix. Depression that doesn’t trace back to anything specific. Irritability that comes out of nowhere. Losing muscle even though you’re still hitting the gym. Gaining fat around the midsection no matter what you eat.
These aren’t personality traits. They’re symptoms.
Some men notice decreased strength. Workouts feel harder. Recovery takes longer. Others notice changes in mood that don’t line up with what’s happening in their life. Everything is fine on paper, but they feel flat. Checked out.
And then there are the physical markers. Increased abdominal and visceral fat. Gynecomastia (accumulation of fat tissue in the chest, driven by estrogen and prolactin excess, which correlates with insulin resistance). These are real, measurable hormonal shifts, not just cosmetic complaints.
Men live with these symptoms for years. Some never connect the dots.
Why Your Doctor Doesn’t Bring It Up
This isn’t your doctor’s fault. It’s a system problem.
Conventional medicine is built for acute care. Car accidents. Surgeries. Infections. Emergencies. It saves lives every day, and it does that well. But optimization and longevity are simply not part of the training. They’re not part of the philosophy.
Colin Renaud, PA-C, who practices functional medicine and has spent over a decade treating men with hormonal issues, puts it plainly: “The conventional medical model just doesn’t do a great job addressing longevity. It’s not that they’re doing it wrong. It’s just not part of the philosophy.”
So a man walks in with a testosterone of 320, reports fatigue, low libido, and depression, and his doctor says he’s fine. That doctor isn’t lying. Within the system he was trained in, 320 is technically within range. The visit is 15 minutes. The box is checked. Move on.
The system treats disease. It waits until something breaks. It does not look at a man functioning at 40 percent of his capacity and think, “We should fix this.”
That gap between “not sick” and “actually healthy” is where millions of men are stuck.
The Stress Factor Nobody Discusses
You can eat clean. You can train five days a week. You can take every supplement on the shelf. And your testosterone can still tank.
Why? Stress.
The HPA axis (hypothalamic-pituitary-adrenal axis) is your body’s stress response system. When it’s running hot all the time, it burns through your hormonal resources. Cortisol goes up. Testosterone goes down. At a cellular level, chronic stress burns out your body’s ability to produce hormones efficiently.
Renaud is blunt about it: “Stress is one of the most toxic things on the body, physically, mentally, spiritually, physiologically.”
Think about what modern life looks like for most men. High-pressure jobs. Financial strain. Poor sleep. Screen time until midnight. Maybe kids on top of all of it. That’s a recipe for cortisol dominance.
And here’s something most guys in the gym don’t want to hear: overtraining is a form of chronic physical stress. If you’re crushing two-a-days with no recovery days, running on five hours of sleep, and wondering why your energy is in the gutter, you might be driving your testosterone into the ground while trying to build it up.
Vitamin D deficiency plays a role too. If you live in the northern half of the country, especially New England, your levels are likely low from October through April. Vitamin D is directly tied to testosterone production. Low D, low T.
Stress, sleep, and nutrient status aren’t footnotes. For a lot of men, they’re the main story.
What an Actual Evaluation Looks Like
Most men who get their testosterone checked get one number: total testosterone. Maybe free testosterone if the doctor is thorough. That’s it.
One number doesn’t tell you much.
A real evaluation looks at the full picture. Total testosterone and free testosterone, yes. But also estrogen (estradiol), because testosterone converts to estrogen via aromatase, and that ratio matters. Cortisol, because if stress hormones are elevated, testosterone production suffers. A full thyroid panel, not just TSH. Fasting insulin, because insulin resistance and low testosterone travel together. Vitamin D. Prolactin. A detailed lipid breakdown.
Then there’s the conversation. How do you sleep? What does your diet look like? How much do you drink? What’s your exercise routine? Are you under chronic stress? What medications are you on?
That’s the difference between checking a box and actually understanding what’s going on inside a man’s body.
And the data backs up taking this seriously. The 2023 Traverse Trial, a large-scale study, showed that testosterone replacement did not increase the risk of heart attacks or strokes. Separate research has shown it doesn’t cause prostate cancer. Meanwhile, men with low testosterone carry greater risk for serious conditions (heart attack, stroke, cancer) because the absence of the hormone drives poor long-term health outcomes.
Leaving low testosterone untreated isn’t the safe, neutral choice people assume it is.
What Comes Next
If any of this landed, the move is simple. Get a blood panel that goes beyond total testosterone. Find a provider who looks at the full picture, not just the one number. Someone who will ask about your sleep, your stress, your diet, and your goals before writing a prescription or telling you you’re fine.
Men over 35 especially should know their baseline. Not because something is necessarily wrong, but because you can’t fix a decline you never measured.
A man at 320 is “normal.” But he doesn’t have to stay there.
About the Author: Colin Renaud, PA-C practices at Med Matrix (medmatrixusa.com), a functional medicine clinic in South Portland, Maine specializing in hormone optimization and metabolic health for men. He holds fellowship training in functional medicine and has spent over a decade helping men understand the difference between “normal” labs and optimal health.