I do fartlek and pyramid running and I sometimes go down to the track and run about 5km.
From the guardian.co.uk
They've all finished the fartlek, it seems, and are walking the rest of the way back to Iten.
From the guardian.co.uk
Fartlek hill training in the week will help as part of a longer run.
From the guardian.co.uk
Fartlek is a technique that was developed in Sweden in the Thirties to improve the fitness of the national ski team.
From the telegraph.co.uk
The advantage of fartlek is you don't have to keep an eye on your watch or know the distances you are running.
From the guardian.co.uk
Fartlek is a common form of training around the world that involves alternating fast bursts of running with slow recovery jogs.
From the guardian.co.uk
More examples
A method of athletic training (especially for runners) in which strenuous effort and normal effort alternate in a continuous exercise
Fartlek, which means "speed play" in Swedish, is a form of conditioning which puts stress on the whole aerobic energy system due to the continuous nature of the exercise. ...
(Fartleks) Literally speed play. These are any form of intervals in which the emphasis is on enjoyable speed rather than the discipline usually associated with intervals. This tends to produce a more effortless version of good running form.
A training technique, used esp. among runners, consisting of bursts of intense effort alternating with less strenuous activity
A Swedish word meaning "speed play," it is a training technique based on unstructured changes in pace and intensity. It can be used instead of timed or measured interval training.
Swedish word meaning speed play. This is an ad hoc form of interval training where you run fast and slow as you feel - taking in sprints up hills, down hills, different surfaces (grass, sand, road).
A Swedish term meaning speed play. A type of workout which allows the runner while on a continuous run to use fast, moderate, or slow periods of running alternated as desired by the runner. This workout is both aerobic and anaerobic.
A conditioning method that uses bursts of speed interspersed throughout a conditioning ride. Similar to interval training, but less structured.
This is a common term in running that has been somewhat butchered over time. The original meaning comes from the Swedish (someone please correct me if I have the wrong nationality) for "speed play". ...