Try running a mile under 6 minutes—in swim fins.
Zach Miller, a recent graduate of Brunswick High School in Maine, broke a Guinness World Record by running a 5:48 mile in swim fins. The previous record was 7:56 ran by Ashrita Furman in 2010. Miller, who has a mile PR of 4:52, told the Bangor Daily News that the key to running fast in swim fins is lifting your feet higher.
This could be a great mile workout if it didn’t look so silly.