What this Navy SEAL's '40% rule' can teach you about success

Jesse Itzler felt he was in a rut. So he asked Navy SEAL David Goggins to live with him for 31 days, during which Jesse would do anything David told him to do.

Jesse would later write "Living With A Seal" documenting the grueling experience of getting whipped into shape by one of the toughest men on the planet. They ran through snow storms, jumped into a frozen lake, and did lots and lots of push-ups.