Over decades of research sport scientists have proven that monitoring of either cortisol or testosterone in isolation provides only an incomplete picture of the bodily status. 

Combining them into testosterone-to-cortisol ratio provides a more comprehensive and accurate picture than either hormone alone, as it enables the analysis of the balance of anabolic and catabolic processes.

Interpretation of the testosterone-to-cortisol individually is basically simple: when the ratio is decreasing, especially when decreasing below the average individual values, stress and load is accumulating and this trend should not continue overly long. In this state, the body is most probably catabolic and no progress is taking place in the tissues – or performance.

Conversely, when the ratio is increasing, and especially when the increase is exceeding the average individual values, the body is in an anabolic state, the tissues are rebuilt and components of the increased performance are present.

Testosterone-to-cortisol ratio is in clear conjunction with performance and anabolism – and the ratioed values are in tight correlation with near-term adaptive capacity and performance.