The reported prevalence of low energy availability (LEA) in female and male track and field athletes is between 18-58% with the highest prevalence among athletes in endurance and jump-events. In male athletes, LEA may result in reduced testosterone levels and libido along with impaired training capacity. In female track and field athletes, functional hypothalamic amenorrhea (FHA) as consequence of LEA has been reported among 60% of elite middle- and long-distance athletes and 23% among elite sprinters. Health concerns with FHA includes impaired bone health, elevated risk for bone stress injury, and cardiovascular disease. Furthermore, LEA negatively affects recovery, muscle mass, neuromuscular function, and increases the risk of injuries and illness that may affect performance negatively. LEA in track and field athletes may occur due to intentional alterations in body mass or body composition, appetite changes, time constraints, or disordered eating behaviour. Long-term LEA causes metabolic and physiological adaptations to prevent further weight-loss, and athletes may therefore be weight stable, yet have impaired physiological function secondary to LEA. Achieving or maintaining a lower body mass or fat levels through long-term LEA may therefore result in impaired health and performance as proposed in the Relative Energy Deficiency in Sport (RED-S) model. Preventive educational programs and screening to identify athletes with LEA is important for early intervention to prevent long-term secondary health consequences. Treatment for athletes is primarily to increase energy availability and often requires a team approach including a sport physician, sports dietitian, physiologist, and psychologist.