I did a series of intervals totaling 4.3K, changing it up a bit at the end in order to keep them going, and on pace. I did a 300 jog after each 600, and either 100, 150, or 200 jog following everything else. I shortened the rest time for the last three down to 100m.
1600m warm up
4 X easy strides
600m, 300m, 600, 300, 600, 300, 600, 300, 400, 300.
This same workout was better than last Tuesday's, as I shortened up the rest and hit better overall times. This run left me feeling energized.