Marine Corps Gen. Joseph Dunford earned the nickname "Fighting Joe" for a reason — he's tough, and he's pretty fast, too. At 61, the chairman of the Joint Chiefs of Staff ran the Boston Marathon on Monday, completing the race is just under 4 hours and 50 minutes. 

Dunford wore a "Team Kelly" shirt to honor for Marine 1

Lt. Robert Kelly, the son of Homeland Security Secretary John Kelly, who was killed in Afghanistan in 2010, a Joint Staff spokesman told

.