In his excellent Middle Distance Outline Guide, coach Joe Rubio provides the following chart as guideline for setting recovery rates for each workout pace.
400 pace: 8x (e.g., 100 in 12. 12 x 8 = 96 seconds recovery)
800 pace: 4x (200 in 30. 30 x 4 = 120 seconds recovery)
1500 pace: 2x (400 in 70. 70 x 2 = 140 seconds recovery)
3k pace: 1x (800 in 2:30. 150 seconds x 1 = 2:30 recovery)
5k pace: 0.75x (1600 in 5:20. 320 seconds x .75 = 240 seconds recovery)
10k pace: 0.50x (3200 in 11:20. 680 seconds x .5 = 340 seconds)
tempo pace: 0.25x (3200 in 12:00. 720 seconds x .25 = 180 seconds recovery)
It is not specified what the athlete should do during the recovery. Possibly because it is more or less obvious, but this issue is unclear to me. I imagine that for 5k, 10k, and tempo (which for Joe Rubio is about HM pace) pace workouts the athlete should keep moving, so these would be jog recoveries, and that the 400 pace reps would call for standing still or very slow walking during the recovery. However, what should be done during the recovery time when performing 800, 1500 and 3k pace workouts?