What is the Origin of Energy Availability Index?

This index is fundamentally established within sports science and exercise endocrinology to assess the risk of the Female Athlete Triad or similar hypofunction states in any sex. It quantifies the energy supply relative to demand.

What is the Mechanism of Energy Availability Index?

When the index falls below established thresholds, the body initiates protective down-regulation of non-essential, energy-intensive processes. This often manifests clinically as suppression of the hypothalamic-pituitary-gonadal axis, leading to reduced sex hormone production and compromised immune surveillance.

Energy Availability Index ∞ Area

Energy Availability Index

Meaning

The Energy Availability Index is a critical physiological ratio quantifying the energy remaining for bodily maintenance and reproduction after accounting for basal metabolic rate and exercise expenditure. A healthy index ensures that essential endocrine functions remain prioritized. Low availability signals a state of energy deficit to the body.