You may not know his name unless you are into yoga, in which case you know Krishna Pattabhi Jois as the man who brought Ashtanga yoga to the west. He passed away at the age of 93. In the picture that accompanies this article, he is an incredible 90 years old, and clearly going strong. You can learn more about him here, or visit his official website to see absolutely amazing pictures and learn more about his teachings. 

Namaste.