Overtraining and Eating Disorders
Let's talk about bad stuff.
Some warning signs include deliberate self-starvation, intense fear of weight gain, sensitivity to cold, and hair loss.
Bulimia - A medical condition characterized by insatiable overeating, involving a distorted body image and bouts of overeating followed by depression and self-induced vomiting, purging, or fasting.
Bulimia-related purging can result in a loss of valuable minerals and nutrients, creating irregular heartbeats and an increase in the potential for heart failure and death. Because of their binge-purge cycle, victims of Bulimia often maintain normal body weights, so it is difficult for outsiders to spot this condition.
Overtraining - Training too hard or for too long, past the point of healthiness.
This condition is a rare psychological state mostly found in competitive athletes, but it is still possible to experience as a normal citizen. Typical signs include insomnia, fatigue, headaches, elevated morning pulse, and decreased resistance to colds, sore throats, and other illnesses.
To learn more: http://www.active.com/health/articles/what-is-overtraining
Moderation is the key.
Best of luck,