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)