Researchers of life extension are a subclass of biogerontologists known as "biomedical gerontologists". Gerontologists note the lack of research regarding and the difficulty in defining frailty. His claims are considered to be a myth by gerontologists. His continued competition at his age attracted the attention of gerontologists. This type of case is classified by gerontologists as "partially validated". Social gerontologists are responsible for educating, researching, and advancing the broader causes of older people.