What would cause someone to have a huge burst of energy days before they become ill? this happens to me sometimes.

Energy: I am not sure what you mean by ill - viral infection? If your immune system is impaired, you might feel run down then catch a cold or other virus more easily. A sudden burst of energy, as you describe, may just be a coincidence. Or it may have a biochemical cause, like a catecholamine release. Frequent bursts of energy could signal bipolar disorder and should be evaluated promptly.