Aerobic endurance / speed training :

You will be employing Unit Running as a method of increasing your aerobic endurance. Unit running combines both aerobic and anaerobic running conditions. One unit consists of 15 minutes of work. The unit (or 15 minutes) is divided into the continuous running of a steady pace and interval sprint training. For example, 8 minutes continuous running, 7 minutes interval training.
The guidelines to follow include: ƒ 

Your heart rate should be no less than 150 beats per minute during the continuous running phase.
ƒEach sprint needs to be run at 100% effort.
The recovery between each h sprint should be a light jog back to the start position. ƒ 
For us on accelerating as powerfully as possible from a standing start.
Eac h unit follows direct try from the previous one. ƒ 
The following is an example of how we might complete a session of 4 units:
10 minutes continuous running + 6 x 50m sprints 
7 minutes continuous running + 10 x 30m sprints up a steep hill 
8 minutes continuous running + 8 x 40m sprints
6 minutes continuous running + 8 x 80m sprints