What Founders Should Track in Blood Work

Here is the line I open every coaching engagement with.

Your business is a function of you. You are the only non-substitutable asset on the org chart. Your VP of Sales can be replaced in 90 days. Your tech lead can be replaced in 120. You cannot be replaced. Not because of ego or charisma. The entire mental model of the company lives in your head, and there is no backup file.

That makes your biology the highest-leverage capital allocation in the company. And almost every founder I meet is making that allocation by accident.

I spent 2024 meeting roughly 300 Nordic CEOs running €1M+ companies. Here is what I saw consistently: they could tell me their churn rate to two decimal places, but they could not tell me their resting HRV. They knew the exact cash runway of the company to the day. They had no idea what their own ferritin was. (This is also, incidentally, one of the mechanisms behind why Nordic founders stall at €1M ARR depleted biology biases every decision toward the safer, statistically worse option.)

That's a category error. They were treating biology like health. Something you address when symptoms appear, paid for out of personal time. Biology is capital. You manage it continuously, as a business operating expense, because it directly determines the throughput of every other asset the company owns.

Annastiina Hintsa, CEO of Hintsa Performance, said it cleanly in her 2021 McKinsey interview: wellbeing is the foundation of sustainable high performance, not a reward for it. For founders, the implication is harder: when you are the foundation, your biology is the foundation. The company cannot scale past it.

A few numbers, because this needs to land properly.

RAND Europe put the cost of too little sleep at more than half a trillion dollars a year across five OECD countries. The same work found that people sleeping under six hours a night carry a 13% higher risk of death than people sleeping seven to nine. That is a population-level number, but for a founder it compresses. You are not making widgets. You are making decisions, and the cost of sleep-deprived decision-making compounds harder when stakes are higher.

McKinsey separately quantified the organizational cost of insufficient sleep: after roughly 17–19 hours of wakefulness, decision-making performance is equivalent to that of someone with a blood alcohol level of 0.05%, the legal driving limit in most countries. Most founders making €500k+ decisions at 10pm on a Tuesday are operating in this zone and have never been told it.

And these are population averages. The cost is higher for founders because:

• The decision quality of a single CEO touches every employee's work for the next 12 months.
• Recovery capacity drops with age while decision complexity stays constant.
• No one is checking. Your CFO will catch a €5,000 expense error. No one catches the €500,000 decision you made on five hours of sleep.

The "wait until something breaks" model assumes you will notice the break. The actual pattern is that founders normalize the degraded baseline. Peter Attia frames this as the slow slide from healthspan into dysfunction, 10–15 years before it becomes visible. By the time you notice, you have already lost the optionality to fix it cheaply.

Continuous biology tracking is the proactive alternative.

Treat biology like a balance sheet with four asset classes. Each quadrant has one primary metric you track, one secondary metric you watch, and a quarterly review cadence.

Quadrant 1. Cardiovascular Capacity

Primary metric: VO₂ max (mL/kg/min)
Secondary: Resting heart rate, blood pressure
Review cadence: Annual VO₂ max test, weekly resting HR trend

This is the foundation. VO₂ max is one of the strongest predictors of all-cause mortality we have. Peter Attia covers the Mandsager 2018 study showing people in the bottom 25% of cardiorespiratory fitness had about five times the mortality rate of the elite tier. For a founder, the difference between the 30th and 75th percentile of VO₂ max is roughly equivalent to the cardiovascular age of someone 10–15 years younger.

The annual measurement costs €100–€200. The training protocol is four Zone 2 sessions per week of 45 minutes, plus one harder VO₂ max stimulus.

Quadrant 2. Hormonal Balance

Primary metric: Free testosterone (men), full sex hormone panel (women)
Secondary: Free T3, cortisol diurnal slope, DHEA-S
Review cadence: Quarterly blood panel

Hormones are the leading indicators. They shift before you notice symptoms, sometimes 6–12 months before. Tracking quarterly catches the drift while there is still time to correct cheaply.

The full panel I recommend includes both T3 and reverse T3, free testosterone (not just total), and a salivary cortisol diurnal slope (not a single morning draw). Most GP panels skip all four. Covered in detail in 4 Blood Markers GPs Miss in Founders.

Quadrant 3. Cognitive Performance

Primary metric: HRV trend (4-week rolling)
Secondary: Resting heart rate at night, deep sleep duration
Review cadence: Weekly HRV review, daily wearable check-in

HRV is the leading indicator for nervous system load. When the trend drops, your decision-making is already compromised, even if you do not feel it yet. A 4-week declining HRV trend in a founder is the equivalent of a leading-indicator dashboard going red. Most founders are still reading lagging indicators (revenue, energy levels) and missing the warning.

The peer-reviewed research on sleep and decision-making is unambiguous: sleep deprivation impairs the prefrontal cortex specifically, and caffeine does not rescue the impairment. The wearable trend gives you visibility into a process you cannot self-report accurately.

Quadrant 4. Recovery Infrastructure

Primary metric: Sleep stages (deep + REM duration, not just total hours)
Secondary: Wake events, time-to-sleep, room temperature
Review cadence: Weekly trend review

Recovery is the asset class founders consistently under-allocate to. The Hintsa McKinsey interview includes the story of a CEO who slept six hours a night, thought he was fine, and after Dr. Aki Hintsa challenged him to try eight hours for two weeks, said: "Oh my God, I'm seeing colors. For the first time I am actually seeing colors." He had normalized a degraded baseline.

The fix is not "sleep more." The fix is to track the stages, not just duration. Seven hours of fragmented sleep is biologically different from seven hours of consolidated sleep. A consumer wearable (Oura, Whoop, Garmin) gives you usable trend data over 4–8 weeks.

The structural innovation is the quarterly review. You already do this with your business. You do it for your biology this way:

Date and duration. Block 90 minutes. Once a quarter. Treat it like a real board meeting: no Slack, no phone, no interruptions.

Required inputs. Pull the data: latest blood panel, last 90 days of HRV trend, last 90 days of sleep data, current weight + body composition if you track it, any subjective notes you kept (energy, mood, decision quality).

The four questions.

• Cardiovascular: is my VO₂ max number on the trajectory I want by age 60?
• Hormonal: which markers shifted this quarter, and in which direction?
• Cognitive: what was my average HRV this quarter vs last? What did the dips correlate with?
• Recovery: what was my average deep sleep duration? Did anything systematically degrade it?

The output. One page. Bullet points. Same format every quarter. Filed in a folder. You should be able to review the last 8 quarters in one sitting.

This sounds excessive until you do it. After two quarters, you start seeing patterns no annual physical would catch. After four quarters, you have a baseline. After eight, you have something approaching real asset management.

The full protocol costs less than most founders expect.

• Annual VO₂ max test. €100–€200
• Quarterly blood panels (4 per year). €800–€1,600
• Consumer wearable. €300–€500 (one-off)
• Cortisol diurnal panel (2 per year). €120–€180
• 90 minutes × 4 quarterly reviews. Your time

Total cash cost, year 1: ~€1,300–€2,500.

Compare that to:

• One bad strategic decision made on five hours of sleep.
• One missed early warning sign on cardiovascular drift.
• One quarter of degraded cognition driving suboptimal hires.
• The compound cost of a 6-month slide in decision quality that nobody flagged because nobody was tracking.

For a founder running a €1M+ company, the cost of not doing this is measured in lost opportunity, not lost cash. The €1,300 panel is the cheapest insurance you will ever buy.

They confuse biology with health. Health is reactive. You address it when something breaks. Biology is proactive. You manage it continuously because it drives everything else.

They run one panel and forget. A blood panel without a follow-up is a snapshot, not asset management. Trend data is the entire value. One data point is a vibe.

They optimize the visible metrics. Steps, calories, gym attendance. These are surface-level metrics. VO₂ max, ferritin, HRV trend, sleep stages. These are the ones that actually matter. Pay attention to what your wearable cannot fake.

They wait for the quarterly review they will "definitely do later." The quarterly review is the operational discipline. Without it, you have data but no system. The 90-minute calendar block is non-negotiable.

Open your calendar.

Block 90 minutes, 12 weeks from today. Call it "Biological Q1 Review."

Between now and then:

• Book a VO₂ max test (€100–€200).
• Book a comprehensive blood panel (€200–€400).
• Wear a sleep + HRV tracker for the full 12 weeks.
• Take 5 minutes a week to note one subjective observation about energy and decision quality.

When the 90-minute block arrives, sit down with all of it. Write a one-page summary. Use the four questions above.

Then schedule the next review for Q2.

• McKinsey. How wellbeing improves performance: interview with Annastiina Hintsa
• McKinsey. The organizational cost of insufficient sleep
• RAND Europe. Why sleep matters: the economic costs of insufficient sleep
• Peter Attia. VO₂ max and longevity (Mandsager 2018)
• PMC. The Cost of Sleep Lost: Implications for Health, Performance, and the Bottom Line