Just how fast is Usain Bolt? On Sunday, the 25-year-old Jamaican proved again why he's considered the fastest man alive and the greatest sprinter in history — demolishing the 100m final with a new Olympic record of 9.63 seconds, despite being hobbled by back injuries. He claimed gold again in Thursday's 200m dash, with a 2012 world-best time of 19.32 seconds, becoming the first runner ever to sweep both events in back-to-back games. Here's a look at Bolt's superhuman quickness, by the numbers:

Seconds in which Bolt ran the 100m in London, an Olympic record

Hours it would theoretically take for Bolt to complete a full 26-mile marathon if he somehow managed to maintain that speed. The current world marathon record is 2 hours, 3 minutes, 38 seconds

Seconds it took for Bolt to run the 100m in a 2009 Berlin race — the fastest time recorded in history and the current world record

Feet by which pioneering Olympic sprinter Thomas Burke would have trailed Bolt at the finish line if he had time-traveled to 2012 to compete in the 100m. In 1896, Burke finished the 100m sprint with a then-record time of 12 seconds

Sprinters in Olympic history who have finished the 100m in under 10 seconds 

Seconds in which Bolt ran the 200m final in London. Jamaica took home all three medals in the event, with Bolt countrymen Yohan Blake and Warren Weir finishing silver and bronze, respectively

Miles per hour at which Earth's top runners (including Bolt) max out

Miles per hour the world's fastest land animal, the cheetah, can reach. A cheetah would be able to run the 100m in 5.8 seconds

5'9" to 6'3"
Average height of most world champion-level sprinters, according to the Journal of Sports Science & Medicine

Usain Bolt's height in feet. "For decades, sprinters have been getting taller," says NPR, "propelled upward by a simple law of physics": Taller runners have a higher center of gravity, and thus can fall forward faster 

The average ratio between fast-twitch muscles and normal, slower muscles in the quadriceps of average humans

Usain Bolt's likely quad ratio, meaning that 90 percent of the muscles in his quadriceps are of the fast-twitch variety. "Usain Bolt was made to sprint," says Deadspin, "while the rest of us are born to jog."

Sources: ESPN (2), New York Times (2), Fox SportsLiveScience, Slate, NPR, Deadspin