Fartlek, in its purest form, is unstructured speed work. “Speed play” is its literal translation from Swedish. Now, I’m as guilty as anyone else who has ever called a structured interval workout done off the track a “fartlek” session, but if we’re being honest that’s not fartlek: it’s just an interval workout. A fartlek is simply a series of faster pickups with a recovery walk or jog in between. It’s technically an interval workout, yes, but the length and speed of the pickups, as well as the recovery periods in between, are not pre-planned and totally up to you in the moment. Here are the details:
What: Pick an object off in the distance, be it a tree, rock, telephone pole, top of a hill, or intersection, and run to it as fast as you want. Once you reach said object—or whenever you want, really—slow it down to a jog or even a walk. Repeat this process the rest of the the run, varying the number, duration, and intensity of your pickups as you please. (Pro tip: If you want to analyze the workout afterward, hit the lap button on your GPS watch when you start/stop a pickup, but don’t look at it while you’re running.)
Why: Mostly because it’s fun! But it’s also a great workout. Fartlek is an effective way to get in some faster running without the pressure of hitting a set pace or a prescribed distance. You can make the workout as hard or as easy as you want.
Warmup/Cooldown: Even though the fartlek itself is unstructured, you still want to make sure you get in a good warmup and cooldown. Warm up before the workout with 15-30 minutes of easy running followed by a set of drills and 4-6 x 20-second strides (i.e., accelerate for 5 seconds, spend the next 10 seconds at near-top speed, and then gradually decelerate to a jog over the final 5 seconds. Catch your breath for 40-60 seconds and then repeat 3-5 more times). Cool down after the workout with 5-15 minutes of easy running.
Where: Anywhere, but ideally outside! Fartlek was meant for forest trails but it works just as well on the roads. You could also do it on a treadmill, speeding up and slowing down whenever you please.
When: You can do fartlek any time but it’s best utilized early in a training block when you’re just starting to do speed work again. Fartlek is also a great way to break up the monotony of base work, or it can be used a substitute for a track workout or structured interval session if you’re feeling burnt out on chasing numbers.