Interval training refers to bouts of running for a given period of time or a specified distance. Rest is provided between intervals to facilitate and manipulate levels of recovery; the longer the rest interval the greater the level of recovery.

This rest period allows the energy tanks time to refuel and helps dictate the type of fuel mix fitness to be developed.

The sooner the refuelling process, the greater your chances of repeating a fast interval - which is basically what fuel mix fitness for rugby is all about.

Interval combinations include:-

1. typical match interval work time, typical match rest time e.g. 20 second interval (i.e.80m shutlle with 2 down-ups), with 30s rest. Best used late pre-season and in-season
   
2. long interval work time, short interval rest time e.g. 400m interval with 45s rest. Work time longer than rest time therefore developing fuel mix fitness with an aerobic emphasis. Because the rest is short you cannot run each interval fast! Best used early pre-season.
   
3. short work time, long rest time e.g. T Run above using Grid Training Poles with 90s rest. Rest time lot more than work time so anaerobic energy has time to replenish. Best used all year round!