If you can run 1 mile in sub 8 minutes: run 1 mile (1.6k) to equal or beat your last 1 mile time. Rest that amount of time, then run 1 mile (1.6k) . Attempt to keep the same pace ( or faster). ( this amounts to 2 miles (3.2k) in total.
If it takes you longer than 8 minutes to run a mile, run 1K as fast as you can; rest the amount of time it took you to do the 1st 1k. Then run 1 k again. ( 2k in total, not miles)
If your 1 mile (1.6k) time is between 8 and 9 minutes you can choose which task you feel will benefit you more. But we are looking at pace and speed if possible.
(new runners feel free to pick 400, 600, 800m as your distance)