Ever wondered what it feels like to stand on top of the world? Eighty-one-year-old alpinist Yuichiro Miura should know: He's done it three times since turning 70. He became the oldest person to scale the world's tallest peak, Mount Everest, in May last year, a remarkable feat that spurred the government to name a state award in his honor. It's rather fitting, then, that the Miura Award is handed out to those who "challenge themselves to the limits of human potential."

Sitting at a table in his Tokyo office late last month, Miura appears to be pondering whether he had indeed exceeded his own limits at breakfast a few hours earlier.

"I had some yogurt, apples, nattō (fermented soybeans) and eggs for breakfast. In fact, I had four eggs . . . maybe I should skip lunch," he says.