Fartlek

Fartlek is a form of athletic training combining continuous and interval training. This can be done either by sprint bursts within a longer Endurance session, or intervals of increased intensity at the same pace - e.g. hill fartlek involves a constant pace but bursts of increased gradient.

Fartlek training is intended to improve aerobic and anaerobic training, and help Sport players in their performance.

Fartlek is a Swedish word that means "speed play". This form of training was developed in 1930 by Swedish national trainer Gösta Holmér ("Gösse"), and is still popular as effective method of training in middle and long-distance running. Also Jeff Galloway has supported this idea of training in his book named "Marathon: You Can Do It." He claims it can reduce times dramatically from marathon to marathon.