Outside's chief inspiration officer, 36-year-old ERIC GREITENS, is a master of getting things done. Like becoming a Navy SEAL commander with four tours, earning a Rhodes scholarship and a Ph.D., running 12 marathons and three ultramarathons, and now juggling operations for his own philanthropic organization with public speaking engagements, media interviews, writing books, and consulting—while still finding time to run, climb, and practice taekwondo. Here's how he does it: "It's all about energy. Whether you're leading a nonprofit organization, running a private company, doing something outdoors, or conducting military operations—you have to build habits that keep your energy high. This is my formula: (1) Vigorous exercise: Six days a week, I walk out of a gym, a dojo, or off a track pouring with sweat. When I have a great workout, I rarely have a bad day. (2) Good fuel: When I eat clean, quality food during the day, my energy never sags. (3) Good partners: Working with a team of positive people keeps your spirits up. (4) Balance: I pray every day, and I also laugh, a lot. You won't have focus without balance. (5) A goal: A worthy challenge will take care of your motivation for you."