Shoes, Algernon, Pangea, and sea peoples

Summary

I fear we are in the waning days of the People Read Blog Posts About Random Well-Understood Topics Instead of Asking Their Automatons Era. So before I lose my chance, here is a blog post about some random well-understood topics. Marathons are stupidly fast You probably know that people can now run marathons in just over 2 hours. But do you realize how insane that is? That’s an average speed of 21.1 km per hour, or 13.1 miles per hour. You can think of that as running a mile in 4:35 (world record: 3:45), except doing it 26.2 times in a row. Or, you can think of that as running 100 meters in 17.06 seconds (world record: 9.58 seconds), except doing it 421.6 times in a row. I’d guess that only around half of the people reading this could run 100 meters in 17.06 seconds once. This crazy marathon running speed is mostly due to humans being well-adapted for running and generally tenacious. But some of it is due to new shoes with carbon-fiber plates that came out in the late 2010s. The theory behind these shoes is quite interesting. When you run, you mainly use four joints: Hips Knees Ankles Metatarsophalangeal If you haven’t heard of the last of these, they’re pronounced “met-uh-tar-so-fuh-lan-jee-ul” or “MTP”. These are the joints inside your feet behind your big toes. Besides sounding made-up, they’re different from the other joints in a practical way: The other joints are all attached to large muscles and tendons that stretch out and return energy while running sort of like springs. These can apparently recover around 60% of the energy expended in each stride. (Kangaroos seemingly do even better.) But the MTP joints are only attached to small muscles and tendons, so the energy that goes into them is mostly lost. These new shoe designs have complex constructions of foam and plates that can do the same job as the MTP joints, but—unlike the MTP joints—store and return that energy to the runner. A recent meta-analysis estimated that this reduced total oxygen consumption by ...