What changes, decade by decade
Ageing is not one process on one timetable. Cardiorespiratory fitness starts declining in your thirties, blood pressure climbs through your forties, bone loss accelerates around menopause, and by your seventies the numbers that predicted risk in midlife matter less than what you can physically do.
These pages are organised around that: what changes, which tests start being worth their cost, and which of our graded interventions were actually studied in people that age.
Pick a decade
30s
Almost nothing is wrong yet, which is exactly what makes this the useful decade to measure. A single set of numbers now is worth more than any intervention you could start.
3 things that change · Cardiorespiratory fitness starts its long decline
40s
Blood pressure climbs, body composition shifts, and for many women the hormonal transition begins several years before anything is named. This is the decade where a baseline from your thirties starts paying off.
4 things that change · Blood pressure begins its steady climb
50s
Risk calculators finally have enough signal to mean something, menopause completes for most women, and bone loss accelerates. Interventions that were preventive in your forties become therapeutic here.
3 things that change · Menopause completes, and bone loss accelerates with it
60s
The markers that predicted risk in midlife start being outranked by what you can physically do. Falls, hearing, medication load and cognition become the things worth measuring.
3 things that change · Falls become a mortality risk, not an inconvenience
70+
Most of the evidence on this site was generated in younger people, and several interventions that help at fifty are neutral or harmful here. Frailty, protein intake and deprescribing carry more weight than anything on a supplement label.
3 things that change · Protein requirements rise while intake usually falls
One caveat that applies to all of these
Chronological age is a crude proxy. Two people at 55 can be twenty years apart on fitness, metabolic health and function, and the decade pages describe population averages rather than you. Where a marker is measurable, measure it — a number about you beats a statistic about your cohort every time.