Recoveries: 
8 Mins – 120 Seconds
3 Mins & 2 Mins – 90 Seconds

Tough session this and the idea is to try and keep those 8 minute reps consistently at 5k pace. The first one will feel comfortable, but the last one will feel like hell. The middle part of the session is to inject some speed in the legs and induce fatigue and possibly some lactic, so you have to work hard in that final rep.