I know this type of thing has been discussed numerous times, but I really would like some additional input on the matter.
I am a 20 year old sophomore at a fairly competitive D2 school and focus mainly on the 3-10k and am running ~90mi/wk. Anyway, since being home on winter break (and away from the dining halls) I noticed I have involuntarily lost a good deal of weight (5-6 lbs) simply due to not having a constant buffet around. My height is 5'9 and weight is 135, and I recently got my body fat measured to be 3.68%. Is this too low for a distance runner? I realize that carrying excess weight can slow you down, but I don't want to accidentally do myself harm by becoming too thin. This began to concern me a few days ago when I noticed that I would occasionally get tunnel vision upon standing up from chairs, etc. Could this be a symptom of not eating enough?
Any advice/suggestions/experiences would be greatly appreciated; I really would like to fix this before it becomes potentially dangerous to my body and running.