They often form an integral part of an athletes training - allowing them to run at a speed which is greater than they could for a steady run - thereby practicing running at race pace, or even faster, in training to educate your body as to how it feels. The intensity of these sessions will vary, but generally is quite high.

This type of session is the format of many of the types of training explained elsewhere.

Fartleks, most speed work, pyramid and paarlauf sessions are all types on interval session.

It is important to understand the term interval training here as it is a term that, as an athlete, you will often hear and if you go to a track, almost every runner will be doing interval repetitions.

Generally during an interval session "overloading" occurs where levels of oxygen debt and therefore lactate / lactic acid levels are increased to a level that would be unsustainable were the whole session run as a single repetition.

The stress on the body creates adaptation after the sessions, so that the body is better able to cope with the demands placed on it in the future - and hence levels of fitness and performance are increased.

Interval sessions are ideally performed on the track as distance can be measured precisely, but other surfaces can be used, although we'd recommend you don't do them on the roads and impacts at higher speed are greater and a hard surface is never ideal to run on.

Those new to interval training often find they are quite high intensity when moving from steady running quite hard, so build up slowly as your body adapts to what you are asking it to do.

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