Wherever he lands on his endless global tour, Harper—who spends up to 300 days a year on the road—makes the most of his time. "First thing I do when I get to a city is hit the street. I walk. I go for a jog, a bike ride, or a skate," he says. Since his 1994 major-label debut, Welcome to the Cruel World, Harper, 37, and his band, the Innocent Criminals, have played at least 125 shows annually. Sounds exhausting, but Harper's got it dialed: "If I want three days off in Rome, I'll carve it out." Over the years, he's cultivated many friendships—surfers in Australia, Hawaii, Portugal, and Brazil, skaters in Canada and the south of France. "I've got a good collective around the world," he says. (That roster includes Lance Armstrong, Kelly Slater, and Laird Hamilton.) When he's not touring, Harper savors his time at home in L.A. with his wife, actress Laura Dern, and their four kids. But it's never long before he starts to feel the pull of the road again. "At this point, it isn't something I have to do. I do it because I love it. I feel like one of the best uses of my time and energies is making music," he says. "And playing live—there's just something specifically fulfilling about it. I don't know how long I'll tour at this pace, but for now we're keeping it hot."

ADVICE? "Roll around on the concrete. It'll thicken up your skin."