MORE GOOD YEARS · READER RESOURCES
The resource guide
The tests, tools and apps behind the book, in the order the book uses them.
The book names very few products on purpose: what's available changes faster than print. This page is where the names live, and I keep it up to date. You don't need any of it to start. Chapter 4 starts with a notebook and five numbers.
Last reviewed November 2026. Links focus on Europe and the US. Prices and availability differ by country, so check before you buy.
Measure · Two devices I'd keep · Heat and cold · The five dials · Supplements · What I left out
Three rules before you buy anything
Start with a question
Write down what you want to know first: why you're tired at 3pm, or whether your sleep is improving. Then pick the tool that answers it.
Go small first
Buy the cheapest version or borrow one, and test it for a few weeks. The wearable to buy is the one you'll actually wear.
Check once, then live
Look at your data once in the morning, as information rather than a verdict. Trends over weeks matter; one score on one day doesn't.
Wearables and home tests don't diagnose anything. If you have symptoms or a result worries you, see your doctor.
CHAPTERS 4 AND 13
Measure: your baseline in three tiers
Start with Tier 1. Go deeper only when you know what you're looking for.
Tier 1 · Start here
Oura Ring — HRV and sleep trends, comfortable at night. What I've worn for eight years. Membership needed for the full app.
WHOOP — recovery and training load; strong for heavy training. Subscription.
Garmin (Forerunner, Fenix) — GPS and workouts, HRV trend and one of the better VO2 max estimates.
Apple Watch — activity and ECG; less suited to nightly HRV trends.
A home glucose meter from the pharmacy for fasting glucose, or Keto-Mojo if you also want to measure ketones.
A validated upper-arm blood pressure monitor, for example from Withings.
No-tech option: rate your energy 1–10 before coffee and your sleep 1–10 when you wake.
Tier 2 · The blood panel
Ask your GP, or order privately. Make sure the order includes: fasting glucose and fasting insulin, HbA1c, hs-CRP, vitamin D (25-OH), testosterone (total and free) and DHEA-S, and lipids, plus the omega-3 index (a separate finger-prick test, for example OmegaQuant).
Netherlands: Bloedwaardentest.nl (draw at a collection point; build your own panel) or Mijnlabtest.nl (finger-prick at home).
Germany: Lykon, Cerascreen. UK: Forth, Thriva. US: Function Health, InsideTracker. Elsewhere: ask your GP for the list above, or search for a private lab in your country.
A draw at a collection point is more reliable than a finger-prick for most markers. Test fasting, in the morning, at the same lab each time.
Also in Tier 2: the VO2 max estimate from your watch, and body composition from a home scale (Withings, Hume Body Pod). Use the trend, not the single reading.
Tier 3 · With a professional
Epigenetic age: TruDiagnostic (DNA methylation). GlycanAge measures something different: glycans linked to inflammation. Either way it's a snapshot, not your real age.
Gut microbiome: Mybioma (stool test, European lab).
Continuous glucose monitor, 2–4 weeks: the sensor is usually an Abbott FreeStyle Libre; the app turns the data into a story. Consumer programmes include Ultrahuman M1 and Levels. Rules differ per country; some need a prescription.
Lab VO2 max test: a breath-gas exercise test at a sports medical centre (in the Netherlands: a sportmedisch centrum).
Someone to read it with you: a functional medicine doctor, or a coach trained by the Syntony Institute.
CHAPTER 14
The two devices I'd keep
I've tried most of what the market offers. For most readers, two make the cut.
HeartMath Inner Balance
A real-time HRV biofeedback sensor and app, so you can see when you move into coherence while you breathe. Around €180, and the skill stays with you. If you take one piece of technology from the book, take this one. heartmath.com →
A red light panel
For recovery and as evening light without the blue. I use a Sunsbest infrared panel. Whichever you choose, ask for the wavelengths, the irradiance at the distance you'll use it, and the eye-safety instructions. For one body area only, a targeted device such as FlexBeam is an option.
CHAPTER 14
Heat and cold
Cold
Start in your own shower; it costs nothing. When you're ready for more, a proper ice bath with cooling and filtration beats a home-made chest freezer (I've tried both). Mine is from Icetubs.
Never go in alone, avoid breath-holding in water, and skip cold straight after strength training if building muscle is the goal.
Heat
The Finnish research was on traditional saunas, so the one at your gym or spa counts. For home, an infrared sauna is easier to install. Mine is a Clearlight (Europe · US).
Two or three sessions a week, twenty minutes. Replace sodium, magnesium and potassium, not just water.
PART TWO
Tools for the five dials
None of these are required. Each is here because it can answer a question the chapter raises.
Sleep
A sleep mask, blue-light-blocking glasses for the evening, and a bedroom at 16–19°C come first.
If you sleep hot: a cooling mattress cover such as Eight Sleep or Chilipad. To track without wearing anything: Emfit QS under the mattress. Snoring? SnoreLab records it, so you can take it to your doctor.
Nutrition
Log three ordinary days with a food app such as MyFitnessPal or Lifesum, then stop. Want to see your own glucose response? Use a CGM for two to four weeks (Tier 3).
Exercise
A sport watch or chest strap for heart-rate zones and Zone 2. Dumbbells or kettlebells at home are enough for strength. Short on time: CAROL Bike runs short guided sprint sessions. Track progress with your watch's VO2 max estimate or a lab test.
Mind
HeartMath Inner Balance for HRV biofeedback. Meditation apps: Calm, Headspace, Ten Percent Happier. For meditation with feedback: the Muse headband. Focus music: Brain.fm.
Connection
No gadget for this one. Put a weekly walk or call in your calendar, and find your people. Join a group that shares your interest, from a running club to a choir. If health is your thing, the Syntony Institute community is a good place to start.
CHAPTER 5
Supplements
A supplement should answer a question, ideally one a blood test raised. Test first.
Disclosure: I own NoordCode and Livehelfi, so I sell most of what I take. That's why I'd rather you trusted a blood test than me.
My foundation stack (Chapter 5): magnesium, vitamin D with K2 in winter, omega-3 and a multivitamin. Functional foods: whey, collagen and creatine.
You can find the NoordCode versions at noordcode.com, and a wider range of brands at livehelfi.com.
Tried, but not essential
NeuroVIZR (light and sound), Apollo Neuro (vibration wearable), NuCalm (relaxation system) and Nurosym (ear-based nerve stimulation). I've used all four properly, with measurements before and after. Some people love them. It would be dishonest to say they did anything exceptional for me, so I'd spend your budget on the basics first.
What I left out
Products sold on "frequency", "quantum" or "imprinted water" claims, and home inhalation of ozone, CO₂ or hydrogen gas. You won't find them here. Popular doesn't mean proven, and some are unsafe.
Want to go further?
The full technology review
Dr Mark Atkinson and the Syntony Institute review more than 60 health technologies, with honest notes on the evidence and the limits.
The habit checklist
The one-page checklist per chapter, free. Get it on the book page →
Don't have the book yet?
This page is for education, not medical advice. Check with your doctor before you change medication, start supplements or begin cold, heat or fasting practices, especially if you are pregnant or have a heart condition. Disclosure: I own NoordCode and Livehelfi and co-founded the Syntony Institute. I have no paid relationship with the other brands on this page. If I add affiliate links later, I'll mark them, and they won't decide what's on the list.