Guides

How to export your Apple Health data, and what is inside
Step-by-step: export all Health data from an iPhone, what the export.zip contains, how big it gets, and how to read it without double-counting steps.

Median net worth by age: the Federal Reserve numbers
Median US household net worth by age of the head of household, from the Federal Reserve 2022 Survey of Consumer Finances, and how to compare yourself fairly.

VO2 max by age and sex: what the FRIEND registry shows
Median treadmill VO2 max for men and women by decade from the FRIEND registry (Kaminsky et al., 2015), and how to read your watch’s estimate.