Relative energy deficiency in sport (REDs) is a widely adopted model describing how low energy availability (LEA) causes a wide range of deleterious health and performance outcomes in athletes.

Empirical evidence supporting the REDs model is limited.

REDs symptoms may be caused by many factors, independent of or co-occurring with LEA, including poor mental health, disordered eating and eating disorders, poor sleep, infection, injury and undiagnosed clinical conditions.

The Athlete Health and Readiness Checklist (AHaRC) is presented as a multidimensional monitoring tool to identify the likely cause(s) of symptoms and ensure that practitioners select appropriate guidance and treatment, where necessary.