What happens at that age?
The body peaks at different times for different things — some at 20, some at 50, some never.
Almost exactly a peak bone mass
30 yr is later than 4 of the 9 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| brain reaches adult size | 6 yr | 5× | |
| peak sprint speed | 24 yr | 1.25× | |
| peak muscle mass | 25 yr | 1.2× | |
| prefrontal cortex matures | 25 yr | 1.2× | |
| peak bone mass | 30 yr | 1× | |
| peak marathon performance | 30 yr | 1× | |
| vision starts needing help | 45 yr | 0.667× | |
| peak vocabulary | 67 yr | 0.448× | |
| global life expectancy | 73.4 yr | 0.409× |
Worth knowing
- Sprinters peak around 24 and marathon runners around 30, because endurance depends on trainable adaptations that take longer to build.
- Vocabulary keeps growing into the late sixties, one of very few cognitive measures that improves throughout adult life.
Frequently asked
When does the brain finish developing?
The prefrontal cortex continues maturing until about 25, which is the basis for a great deal of policy about young adults.
When do athletes peak?
Roughly 24 for explosive events, 27 for team sports, 30 for marathon and 39 for ultra-endurance. The longer the event, the later the peak.