Exercise & Recovery

Exercise improves brain function, sleep, insulin sensitivity, hormone balance, bone density, and mood. It reduces the risk of almost every chronic disease. If it came in a pill, it would be the most prescribed drug in history.

According to WHO guidelines and large-scale mortality data: 150–300 minutes per week of moderate aerobic activity plus 2 sessions of resistance training per week. Below this, risk curves for heart disease, diabetes, depression, and early death rise sharply.

Zone 2 means a pace where you can hold a conversation — a brisk walk, light jog, or easy cycle. It feels almost too easy, which is exactly why most people skip past it for harder workouts that deliver less.

But 150–180 minutes per week of Zone 2 is the most powerful thing you can do for long-term metabolic health. It builds the number and efficiency of your mitochondria (your cells' energy factories), improves your body's ability to burn fat as fuel, and lays the aerobic foundation everything else — including high-intensity work — is built on. Of all the tools in this chapter, Zone 2 has the deepest and most consistent evidence base: large population studies and controlled trials both point the same direction, which is rare in exercise science.

Muscle is not just for aesthetics. It's your body's largest glucose reservoir — meaning strong muscles improve blood sugar control.

Resistance training is the most effective intervention against age-related muscle loss (which accelerates after 35), and it improves bone density, posture, and metabolism. You don't need a gym — bodyweight exercises work.

None of this works without progressive overload: gradually increasing the difficulty of what you do. Lifting the same weight for the same reps every week signals to your body that no further adaptation is needed — muscle and strength gains stall almost immediately once the stimulus stops increasing. The fix is simple in principle: add a little more weight, an extra rep, or an extra set every week or two, tracked rather than guessed. It doesn't need to be dramatic — small, consistent increases in difficulty over months are what separate people who keep progressing from people who plateau within weeks of starting.

VO2 max is a measure of how well your body uses oxygen during intense exercise — and it's one of the strongest predictors of how long and well you'll live, with effect sizes in longevity studies that rival or exceed not smoking. To improve it: try 4-minute hard efforts (Zone 4–5 — genuinely uncomfortable) followed by 4 minutes of recovery, repeated 4–6 times. Once or twice per week is enough — this is a case where a small, consistent dose of real discomfort outperforms far more total training volume done comfortably.