kleinzy
Kleinzy (noun) : A middle aged man that has the ability to perform athletic feats of a 20 year old. A kleinzy has none of the physical trappings of the aged. His physical ability at that age are rare and wondering. A kleinzy embodies all that is young,youthful and vibrant. A kleinzy defies typical boundary of thought mind and spirit.
A kleinzy can be a person who is, or otherwise wishes to be one. A example of a kleinzy is Lance Armstrong.