How Fast Can a Human Run?

A grizzly bear can run faster than 30 mph. The fastest human ever measured hit 27.6. So how fast can a human actually run, and what stops us? Bob goes up the ladder one speed at a time, from an escalator and a gym treadmill to a T. rex, an NFL player, Usain Bolt and a cheetah, then finds the one race where humans beat almost every animal on Earth. CHAPTERS 0:00 A grizzly is coming. Do not run. 0:30 Every speed: escalator, walking, jogging, treadmill 1:02 T. rex (12 mph) and the elephant (15 mph) 1:32 NFL, school zones and running backwards 2:02 Usain Bolt: 9.58 s and 27.6 mph 2:54 Beijing 2008: the untied shoelace 3:23 1,000 chicken nuggets 3:39 Why we stop: everyone's legs are equally fast 4:18 Why we stop: 0.09 seconds on the ground 4:43 Why we stop: fuel and the hamstring 5:09 17 years without a new 100 m record 5:31 Running on the Moon 5:48 The robot that ran 8.64 s 6:05 Horse, ostrich, cheetah (58 mph) 6:34 The twist: humans are built for distance 7:05 Persistence hunting in the Kalahari 7:24 Man versus Horse 7:40 The 2-hour marathon: Kipchoge, St. Louis 1904, Sawe 8:43 So, how fast can a human run? 9:30 Next: how far can a human fall? PEOPLE & PLACES MENTIONED Usain Bolt (Berlin 2009, Beijing 2008) · Jim Hines (Mexico City 1968) · Eliud Kipchoge (Vienna 2019) · Sabastian Sawe (London 2026) · 1904 Olympic marathon (St. Louis, USA) · Man versus Horse Marathon (Llanwrtyd Wells, Wales) · Kalahari Desert · NASA Langley reduced-gravity simulator (1966) · Humanoid Robot Games (Beijing 2026) · University of Oslo · Harvard University Bob is a stick figure with one problem: he can't stop asking how far things go. How deep, how high, how fast, how long. Every video follows him to the limit, with sources. New episodes Tuesday and Friday. #usainbolt #running #science