Aubrey Marcus is writer, entrepreneur, and adventurer. Some of his writings and experiences can be found on his website, WarriorPoet.us, as well as links to his latest venture, Onnit Labs.

Dr. Dan Engle, MD is a practicing psychiatrist, board certified in psychiatry and neurology. Aubrey Marcus is writer, entrepreneur, and adventurer. Some of his writings and experiences can be found on his website, WarriorPoet.us, as well as links to his latest venture, Onnit Labs.