Excessive Exercise and Threshold of Energy Availability

Edit: This article is specifically for women who chronically undergo large calorie deficits!

I've seen a lot of topics (not losing weight, hair loss, etc.) that are likely associated with the same cause: chronic caloric restriction and excessive exercise.

One common question people should ask themselves is: How much cardio (or exercise in general) is excessive to the point it can be detrimental to ones health?

Anne B. Loucks has researched this topic extensively and, along with Jean R. Thurma, has estimated the threshold at which women may experience negative consequences due to the above mentioned lifestyle choices.

The formula to estimate this predicted threshold follows:

30 kcal/kg lean body mass x·days (at which you are at this deficit)

Energy availability is the amount of calories remaining once you subtract exercise calories from gross calories consumed. Basically, if your energy availability goes below the answer you get from the above equation, you are placing yourself at risk for the aforementioned health concerns - many of which can be quite serious and severe.

Here is the research article:

http://jcem.endojournals.org/content/88/1/297.full?sid=3f3b16d8-b819-47c8-9cc9-88c8451b52dd