Run for Fun: Dangers of undereating and running 

TAMPA, Fla. (WFLA) - In this week's episode of Run for Fun, we focus on a condition that affects many athletes: low energy availability. Low energy availability simply means the body does not have enough energy to support daily functions like organs operating at normal levels. Energy the body needs comes from calories in food. Any physical exercise uses some of that energy, and the body uses what's left for its basic physiological processes. If an athlete has prolonged low energy availability it can lead to a condition called Relative Energy Deficiency in Sports (RED-S)