fartlek
fart·lek
noun
1.
a method of athletic training (especially for runners) in which strenuous effort and normal effort alternate in a continuous exercise
Origin
Borrowed from Swedish fartlek, from fart (“speed”) + lek (“child’s play”).
Related words
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.