Advanced protocols

Once the foundations are in place, there's a set of tools that can add something extra. Some have decent evidence. Many are expensive and oversold. This chapter covers the main ones honestly, and the rule for all of them is the same: only after your Level 1 and Level 2 boxes are green. A sauna won't fix a blood pressure problem caused by five hours of sleep and a bottle of wine a week.

Sauna

The evidence. A Finnish study that followed more than 2,000 men for around 20 years found that those who used a sauna 4–7 times a week had about 40% lower risk of death from any cause than those who went once a week, and later analyses of the same group found lower rates of cardiovascular death and dementia. This is observational: regular sauna users may be healthier in other ways. But it's consistent with shorter trials showing improvements in blood pressure and blood vessel function.

How. A traditional Finnish sauna at around 80–100°C for 15–20 minutes, two to four times a week. Drink water. Infrared saunas run cooler and are less studied.

Avoid it with unstable heart disease or low blood pressure, during pregnancy, after drinking alcohol, or when you feel unwell.

Cold exposure

The evidence. Weaker than for sauna. Cold water immersion reliably increases alertness, and many people report a better mood. Claims about fat loss, immunity and longevity are mostly unproven.

One caveat. Cold immersion straight after strength training can reduce the muscle and strength you gain from it. If building muscle is a goal, keep cold exposure several hours away from lifting sessions.

Avoid it with heart conditions or uncontrolled high blood pressure. Never swim in cold open water alone.

Red light therapy

The evidence. Red and near-infrared light, also called photobiomodulation, has reasonable evidence for some skin outcomes such as fine lines and wound healing, and some evidence for joint pain. Evidence for broader longevity effects is thin. Results depend heavily on a device's power and wavelengths, which vary widely.

If you try it, choose a device with published specifications, protect your eyes, and treat it as a skin tool rather than a longevity one.

Hyperbaric oxygen therapy (HBOT)

The evidence. HBOT means breathing pure oxygen in a pressurised chamber. It's an established treatment for decompression sickness, carbon monoxide poisoning and some wounds that won't heal. A 2020 Israeli study of 35 older adults reported longer telomeres and fewer senescent cells after 60 sessions, which attracted a great deal of attention. It was small and had no control group, and HBOT hasn't been shown to extend healthy life.

Cost and risk. Courses cost thousands of euros. Side effects include ear and sinus injuries from pressure and, rarely, oxygen toxicity. Only use supervised medical facilities.

Others you'll hear about

• Continuous glucose monitors (CGM). Useful as a short experiment, two to four weeks, to learn how your meals, sleep and exercise affect your blood sugar. Not needed long-term for people without diabetes.
• Breathwork classes, compression boots, PEMF, cryotherapy chambers. Limited evidence for longevity. Fine if you enjoy them; not a priority.

How to judge a new protocol

Ask four questions. Is there evidence in humans, not just in mice? Is it from randomised trials, or only associations? What does it cost, in money and time? And what would I give up to do it? If it pushes out sleep, exercise or time with people, it's a bad trade.

Key numbers
4–7 times a week: sauna use linked with ~40% lower mortality in Finnish men.
15–20 minutes at 80–100°C: a typical sauna session.

This week

• Only if your Level 1 and 2 boxes are green: pick one protocol, try it twice a week for a month, and note how you feel.
• Otherwise, skip this chapter's homework and go back to your bottleneck.

Sources: Laukkanen et al., JAMA Internal Medicine 2015 · Laukkanen et al., Age and Ageing 2017 · Roberts et al., Journal of Physiology 2015 · Hachmo et al., Aging 2020