5 Minutes:
Triple Under Practice

3 Rounds
Run 400 (rest 1 min)
Run 400 (rest 1 min)
Run 800 (rest 2 mins)
The run adds up to just about 5k. For those of you working towards something similar this is a good training session. There will be scaling options as well for those who need it.
Wait, what? Triple Unders?