#39

Testosterone, bloodwork and AI. The stack you didn’t know you needed

I got my testosterone tested at 35. The results weren’t what I expected, but the bigger surprise was what my AI dashboard told me to do next.If you’re anything like me (male, 35+), the thought that your testosterone might be dipping has crossed your mind. It definitely crossed mine, so I booked a blood test to find out what was actually going on. Once the results came back, I built a private dashboard to track them, then used it to generate weekly recommendations against my two goals: build more lean muscle and run better.

In this article I’ll show you:

1. What normal testosterone looks like, and why it matters
2. Why you should get bloodwork done every quarter
3. Why AI tools are making sense of your health data
4. How to build your own health dashboard

If you’re in your 20’s, you probably don’t care much about your testosterone. I didn’t (rightly or wrongly). In your 30s, you should start paying attention, because it drives your:

• Libido
• Muscle and strength
• Fertility (sperm production)
• Bone density

…to name a few. As a man, you need to know where you stand. And if it’s low, you need to find out why, and fix it.

1. What “normal” actually looks like

Here’s the first thing that tripped me up: “normal” is a massive range.The best benchmark comes from a 2017 study published in the ​Journal of Clinical Endocrinology & Metabolism. It pooled samples from over 9,000 men across four US and European cohorts and calibrated every lab against the same CDC reference method. For healthy, non-obese men aged 19 to 39, the range came out at 264 to 916 ng/dL (nanograms per decilitre), with the median at 531. UK labs report in nmol/L (nanomoles per litre), so that’s roughly 9–32 nmol/L, with the middle around 18.Read that again. A guy at 10 nmol/L and a guy at 30 nmol/L are both “normal.” One has three times the testosterone of the other. “In range” tells you you’re not clinically deficient. It doesn’t tell you whether you’re anywhere near your best.

Three numbers to find on your report:

• Total testosterone: everything in your blood, bound and unbound. The headline figure.
• SHBG (sex hormone binding globulin): the protein that grabs testosterone and holds on to it. High SHBG means more of yours is locked up.
• Free testosterone: the small slice that’s unbound and available to your muscles and tissues. Total can look fine while free is low, which is why you want both.

My results: Total T: 19.8 nmol/L, Free T: 385 pmol/L, SHBG: 34 nmol/L.

What surprised me: My total testosterone was comfortably within the normal range, but my free testosterone was less impressive than I expected, showing me that a healthy total testosterone number doesn’t necessarily tell the whole story.

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2. Why one blood test isn’t enough

Testosterone isn’t a fixed number like your height. It swings through the day and peaks in the morning, and it reacts to how you slept, trained and ate that week.That’s why the Endocrine Society’s clinical guideline tells doctors to measure total testosterone from a fasted morning sample, then repeat the test to confirm before diagnosing anything. The reason is blunt: roughly 30% of men whose first result lands in the low range come back normal on the retest. One test is a snapshot. A series is a trend. And a trend is the only thing you can act on.I test every quarter because I’m changing things (sleep, training split, nutrition) and I want to know whether they’re working. Three months is long enough for changes to show up in your blood and short enough that you don’t waste half a year on something that isn’t. To keep readings comparable, I book every test the same way: before 10am, fasted, no hard session the day before. For the record, the guideline says otherwise healthy men don’t need to be screened. Quarterly testing is my call as someone running experiments on himself, not a medical requirement.

3. Why AI is your best friend for optimizing your health

Your blood results arrive as a PDF of numbers and reference ranges. Your watch tracks sleep, heart rate and training load in a separate app. Your gym log lives somewhere else again. Nobody is putting those together for you. Your GP has ten minutes and is looking for disease, not performance.That’s the gap AI fills. Give it your bloodwork, your training data and your goals, and it can spot patterns across all three in seconds and turn them into a plan for the week. The biggest lever it pointed to wasn’t a supplement or a training trick. It was sleep. Plain and simple. Also, the research backs it up. In a University of Chicago study published in ​JAMA, ten healthy men with an average age of 24 were limited to five hours a night for a week, and their testosterone fell by 10–15%. The researchers compared that drop to ageing 10 to 15 years. It’s a small study, but the mechanism holds: most of a man’s daily testosterone is released while he sleeps.Look, I know what you’re thinking “I don’t want to give ChatGPT or Claude my data” and that’s valid but, on the other side of your skepticism is a world of truly personalised health insights and action planning that could change your life. One rule I hold it to: AI interprets, it doesn’t diagnose. If anything on my panel looks genuinely off, that’s a conversation with a doctor, not a chatbot but this is certainly helpful and better than what I was doing before AI… which was nothing btw.

4. How to build your own health dashboard

You don’t need to code. Here’s the setup:

1. Get a proper baseline. Book a panel that includes total testosterone, free testosterone and SHBG at minimum. Fasted, before 10am ideally.
2. Set up a dedicated AI workspace. I use a Claude Project you can copy the instructions I created for the project here. Upload your results PDF and write a short brief: age, training history, weekly routine, and the two or three goals you care about. Mine: build lean muscle, run faster.
3. Ask it to build the dashboard. Something like: “Turn these results into a dashboard. Show each marker against its reference range, flag anything in the bottom third, and leave room to add quarterly results.”
4. Feed it your weekly data. Every Sunday, export sleep, training and recovery numbers from your watch and drop them in.
5. Ask for the week’s plan. “Based on my bloodwork, last week’s data and my goals, what are the three changes for this week?” Three, not ten. You’ll actually do three.Every quarter, add the new bloods, doc appointments, anything that allows you to get a clear view on your health really. That’s when it gets interesting: you stop guessing whether the changes worked, because you can see it.

The bottom line

Testosterone isn’t something to panic about at 35. It’s something to measure. Get tested, test again, and put the numbers somewhere that can tell you what to do with them.