A significant insight from Peter Attia’s book Outlive highlights the critical role of cardiovascular fitness in maintaining physical capabilities as one ages. A particular graph from the book has been noted for its impact on personal health perspectives.
The graph is presented below:

In summary, to retain the ability to briskly climb stairs at 75 years old, an individual would ideally need to achieve the top 95th percentile in cardiovascular fitness. Even at this high level, activities like jogging up steep hills would remain challenging, typically requiring the fitness of an elite athlete.
Conversely, individuals with average or low fitness levels may find themselves unable to perform such activities. It is generally considered improbable to transition from an average fitness level to the 95th percentile later in life, underscoring the importance of initiating fitness efforts early.
This understanding often motivates individuals to engage in regular physical activities, such as running or cycling, to proactively build and maintain their fitness levels.
The book itself is highly regarded, and further book recommendations from the past year are available here.

