Glenn, who rode a Mercury space capsule into eternal fame in 1962 and turns 90 Monday, says he still skis and flies his own plane, and plans a cross-country car trip with his wife, Annie, in the fall.
"I'd rather burn out than rust out," Glenn told the Pittsburgh Post-Gazette.
The newspaper said Sunday that while Glenn has maintained a fairly low profile in recent years, he is in good health with a sunny smile and brisk walk. He maintains an office at the John Glenn School of Public Affairs at Ohio State University.
The newspaper called Glenn a microcosm of U.S. history from his boyhood in the Post-World War I era through the second world war and Korea and on into the heroic days of the space race with the Soviet Union when he and his six fellow Mercury astronauts became a symbol of the nation's "can-do" spirit and technical prowess.