Were running into the weekend with this one.
1x (320m fast, 160m easy)
Rest 1min
2x (320m fast, 160m easy)
Rest 2min
3x (320m fast, 160m easy)
Rest 4min
4x (320m fast, 160m easy)
Total: 4800m
Try to control the breathing. These aren't all out efforts on the fast runs, but its definitely not a jog.
If your working on improving your running or breathing and fitness overall, give these books a read.