What defines healthy? It's a good question because one of the dangers of more invasive medical testing and analysis is the finding of abnormal results. Yet healthy as a whole, as an individual, is not the same as healthy blood or healthy cells. A microcosm being, how does one know if he or she is fully recovered from a major ultramarathon? It's going to be mostly how one feels, as various markers will likely subside well before recovery is complete, or remain elevated as the person is a long term athlete.