What is Fartlek? No it is not just a funny word. Fartlek is a Swedish term that means speed play, which is a form of interval training that is found to be effective in improving speed and edurance. Fartlex or interval training allows me to run longer, further, and I find my runs more enjoyable. To be a successful runner I find that it is really important to learn what works best for you while you are out on a run. Do you run best on a track? Do you run best with consistancy and running the same route over and over again? For me personally I run best and am the most disiplined if I run a loop never passing the same mailbox twice during the course of a run. The other asspect which allows me to run to my fullest potential is this funny word called Fartlek. I find that interval running can be as easy or grueling as you wish to make it. Today I ran 5 miles and I can honestly say that I enjoyed myself and if I did not just take a shower I would consider going out for another run.