Row Intervals 
10 x 400m // :40 rest between each
10 x 300m // :30 rest between each 
10 x 200m // :20 rest between each 
10 x 100m // :10 rest between each 

Pulled this from 12 Ways To A 10K on the C2 site. Short frequent (40 of 'em 😬😬) intervals keep your heart rate up. It is recommended that you take the rest intervals as true rests to allow your heart rate to go down. There weren't any pacing instructions so I kept the pace/rate around my goal 10K.