Below are suggested interval distances and the paces you should be running these intervals for your 1/2 Effort workout.

Suggested Workout (5000m)	Suggested Pace		Alternate Workout
10-15 X 400m	1:28.93 1:24.49 - 1:36.94	or	10-15 X 90 seconds
8-10 X 500m	1:55.21 1:49.45 - 2:05.58	or	8-10 X 2 minutes
5-6 X 800m	3:11.64 3:02.06 - 3:28.89	or	5-6 X 3 minutes
4-5 X 1k	3:54.52 3:42.79 - 4:15.63	or	4-5 X 4 minutes
3 X 1 mile	6:31.22 6:11.66 - 7:06.43	or	3 X 6 minutes