10 rounds, each for time, of:
Rest 90 seconds
Sprint 100M then rest 90 seconds. Do it 10 times. Feel free to rest for longer than 90 seconds after the 10th sprint. 100M is the length of the straight part of a standard track. You know, the one that encircles every high school football field in America. Feeling frisky? Run it on the field. This is roughly .06miles on the treadmill; definitely add some loft (elevation). Subs if you must are Row 125M/swim 25M/Airdyne 1/8 Mile/Bike 400M (1/4 mile).