Each 3.9km lap must be completed within a set time

Starting at a leisurely 30 minutes for the first lap and decreasing by a minute each lap thereafter.

The time taken from the original 30 minutes is added to the rest between the laps - i.e. the second lap will have 1 minute rest and 29 minutes running time; the third lap will have 2 minutes rest and 28 minutes allowed for running.​​