The physiological fitness terrain

Health pictured as a landscape with two separate properties: how high you stand, and how stable the ground under you is.

Altitude is fitness

Death is ground level. The higher a person stands, the lower their risk of dying. Here altitude is read from mortality: it is minus the log hazard ratio from the mortality curve of each marker, so a higher value is better.

Local shape is stability

This is how the project reads the landscape's local shape. It is a working interpretation, not a quotation from the book.

Troughs are homeostatic or quasi-steady states: disturbed a little, people return.
Mountain tops are instability: bifurcation and allostatic load. Small pushes decide which way a person falls.
The mountainside is the stress response, where stress is applied and either recovered from (resilience grows) or pushed over a barrier.
Falling from a peak to the next, lower trough is a step jump in biological age.

A schematic, not data: shapes are illustrative.

Diagnoses are overlays, never axes

Disease labels are kept as the yardstick the terrain has to reproduce or beat. See Diagnoses on the terrain.

The shape of a mortality curve is not the same thing as stability. A steep stretch of a hazard curve is only a candidate barrier. Instability is claimed only from within-person drift (Stability) or recovery dynamics (Mountainside).

Origin

The Physiological Fitness Landscape concept is by Brian Fertig and Jack Tuszynski. It builds on Fertig's Metabolism and Medicine, Volume Two: The Metabolic Landscape of Health and Disease (CRC Press), which sets out health and disease as a multi-dimensional topography whose altitude is fitness, with the stress response carrying a system from homeostasis to allostasis or to allostatic overload. The reading of troughs, mountain tops, the mountainside and falls between troughs on this page is the project's own. A formal definition of metabolic fitness is in preparation by Prof. Tuszynski; until then this site uses interim measures.