George W. Bush: avid cyclist
George W. Bush (whose father, George H. W. Bush, celebrated his 90th birthday by going skydiving) was a long-time runner, even finishing the 1993 Houston Marathon in well under four hours. Later, when knee pain made running difficult, he took up mountain biking—and quickly transformed into a zealous rider. Now in his 70s, the 43rd president reportedly still exercises on an elliptical machine, plays golf, and, by all accounts, still bicycles.