<P> Fartlek, which means "speed play" in Swedish, is a training method that blends continuous training with interval training . Fartlek runs are a very simple form of a long distance run . Fartlek training "is simply defined as periods of fast running intermixed with periods of slower running ." For some people, this could be a mix of jogging and sprinting, but for beginners it could be walking with jogging sections added in when possible . A simple example of what a runner would do during a fartlek run is "sprint all out from one light pole to the next, jog to the corner, give a medium effort for a couple of blocks, jog between four light poles and sprint to a stop sign, and so on, for a set total time or distance ." The variable intensity and continuous nature of the exercise places stress on both the aerobic and anaerobic systems . It differs from traditional interval training in that it is unstructured; intensity and / or speed varies, as the athlete wishes . Fartlek training is generally associated with running, but can include almost any kind of exercise . </P> <P> Swedish coach Gösta Holmér developed fartlek in 1937, and, since then, many physiologists have adopted it . It was designed for the downtrodden Swedish cross country running teams that had been beaten throughout the 1920s by Paavo Nurmi and the Finns . Holmér's plan used a faster - than - race pace and concentrated on both speed and endurance training . </P>

What is the difference between interval and fartlek training