Testing & tracking

You can't improve what you don't measure, but most people measure the wrong things. They buy a wearable, collect a thousand data points, and never change a single decision. The goal of testing isn't data. It's to find the one thing holding your health back.

Three levels

The journal and this site sort tests into three levels, cheapest first.

Level 1: Foundational (free, at home). Blood pressure, waist and body fat, your resting heart rate, the five tests of the fitness map, and the daily habits behind them: steps, sleep, smoking and alcohol. Most people find their first red box here.

Level 2: Advanced (the basic blood panel). Blood sugar, lipids and ApoB, inflammation, liver and kidney markers, ferritin, B12 and vitamin D. Only once you're lean and fit.

Level 3: Optimized (the top 1 %). Stricter blood targets, VO2 max, a DEXA scan and your biological age: the level where you could enter the Longevity World Cup.

The full targets for every level are on the Testing page.

The gate

Here is the rule that makes the system work: you belong in the lowest level that still has a red box. You don't move up until every box at your level is green at two 30-day checks in a row.

That sounds strict. It's the point. Someone with high blood pressure and a waist that's too big for their height does not need a DNA methylation test. They need to walk more, drink less and sleep longer, and the Foundational boxes will tell them when it's working.

Your bottleneck

Your first red box is your bottleneck: the single thing that, if fixed, would do the most for you right now. Write it down. It goes at the top of your plan and stays there until it turns green. Everything else is secondary.

Once you know it, choose your seven boxes: one of them is the fix for that bottleneck.

What to track, and how often

Test under the same conditions every time: same time of day, same scale, fasted where required, same lab. Changes smaller than normal day-to-day variation aren't changes.

Getting a blood test

You don't need a hundred markers. You need the right twenty, measured the same way each time. The Testing page lists exactly what to ask for at each level, with a copy-ready list for your GP.

A few things make the result far more useful:

• Prepare the same way every time. Fasted, in the morning, no hard training or alcohol for 48 hours, and not while you're ill.
• Ask a better question. Not "is this normal?" but "is this moving me toward health, or toward risk?" Normal means common. Optimal means lower long-term risk.
• Read patterns, not single numbers. High triglycerides with low HDL and raised fasting insulin tells a clearer story than any one of them alone.
• Retest before you worry. One odd result is a reason to check again, unless it's far outside the lab range. Then see your doctor promptly.
• Don't fix one number by breaking another. Crash diets and overtraining can improve one marker while worsening others.

Most red markers share the same causes: waist fat, too little movement, poor sleep, stress, ultra-processed food, alcohol and smoking. Bad bloodwork rarely happens at random, and the fix is usually the Level 1 list.

Wearables: useful, not essential

A watch or ring is good at steps, sleep timing and resting heart rate trends. It's poor at sleep stages, calories burned, and anything presented as a single "readiness" score. Use it to see patterns over weeks, not to judge a single night.

Don't over-track

If a number wouldn't change what you do, stop tracking it. Anxiety about data is its own health problem, and chasing a perfect score on a device can crowd out the habit it's supposed to measure.

Key idea
Lowest level with a red box. One bottleneck. Retest every 30 days. That's the whole system.

This week

• Do the Level 1 checks on the Testing page. They take about 30 minutes.
• Take the free Longevity Score to see which level you're likely at.
• Write down your bottleneck in one sentence: what it is, and the number you're aiming for.
• Log your results on My Results so you can see the trend.

In the journal

Part 2 of the journal is this chapter on paper: the tier assessment, the gate and your bottleneck, which becomes one of the ten boxes on every evening page.