Health
The only asset that compounds and decays at the same time.
Sleep, food, strength and movement are the levers that decide how well you age, and most people are not short of information about them. What follows is the small number of changes that actually move a measurement, written for a real week rather than an ideal one.
Going deeper
Everything above works. This is what it does not cover.
Written mechanisms are good at explaining what to do and poor at showing what it looks like when it goes wrong. The health lessons are filmed on real cases, including the ones that do not resolve neatly.
Coaching exists for the part no article reaches: your constraints, your week, and the specific thing that keeps breaking after the third attempt.