The following is taken directly from Michael Sandrock's outstanding book, Running Tough, which may be purchased at Amazon.com, or the e-book at us.HumanKinetics.com.
Fartlek Training: Mixing It Up
A long time ago, far away in the woods and fields of Sweden, Gunder Hägg and Arne Anderson ran workouts called fartlek on their way to becoming the top two milers in the world. The term comes from a Swedish word usually translated as "speedplay." Fartlek was popularized by the pair of milers, who knocked loudly on the door of the 4-minute mile in the 1940s.
Let's be honest about something: training is often difficult, seemingly unending work. Just as Sisyphus is doomed to forever push his heavy rock up a steep mountainside, so does it seem that a runner's fate is ceaseless sweat and labor, toil and training. Finish one great workout or long run, and you know in the back of your mind that another is waiting patiently for you later in the week.
The only way to keep your training going consistently, year after year, is to make it fun whenever possible, even while doing a tough workout. Fartlek helps you do that by keeping an element of play in the workout without reducing your hard running.
Remember when you were a kid, playing in your schoolyard on one of these long, magical summer evenings that lingered on and on? Maybe you played "kick the can." Or perhaps you and your friends were out there chasing each other across one of those freshly mowed grass fields, playing tag. You would sprint, then rest, then sprint again, looking over shoulder and laughing a rib-busting, out-of-breath laugh as you tried to stay a step ahead of your friends. How fun running was then, how enjoyable. It was not work; it was a simple and pure pleasure.
That kind of joyful play in running we all experienced as children can be recaptured in a fartlek session. Simply put, fartlek is unstructured fast running over a variety of terrain, interspersed with recovery running.
How far or fast should you run on the hard segments? That's the great thing about fartlek—it is all up to you. There is no coach with a stopwatch telling you when to start and stop, no lines on the track to stay withing, no miles to repeat or meters to sprint. Pick out a lovely pine tree atop a hill, and run hard to the tree, or to a fence, bush, or whatever strikes your fancy.
During fartlek, you might be running along when all at once you or your training partner take off, for no apparent reason. Run fast simply because you feel like it, and stop when you feel it is time. Take a short recovery sometimes, other times take a long recovery before the next hard effort.
How many hard segments should you run, how many total miles, how much warm-up and cool-down? Who knows? Who cares? Save that for another day, another run. This is fartlek: Run hard for as long as you want, just because you feel like it. You will get an excellent workout in without the mental pressures you sometimes have on the track.
Fartlek can take us back beyond our childhoods, back to the primal origins of running, as I discovered on a trip to Kenya. When I was in the Rift Valley training with the young runners, we would sometimes run across pathless fields, the sun hanging low above the Rift Valley escarpment in the distance. I remember thinking, This is how our ancestors must have run when they first stood up on two legs not so far from here.
Maybe those first runners chased antelope or wildebeest to get food, or maybe they were chased by lions or leopards who hoped to make them food. Either way, when they were done chasing or being chased through the valley, I have the feeling that our first ancestors—call them Adam and Eve if you like—would then run for the sheer joy of it, simply because they felt like it. Just as we should sometimes.
Fartlek is less structured than track workouts or repeats on the road, which is just the point: We runners, especially competitive runners, too often are ruled by the clock. During a fartlek workout, run as you were meant to run, with no thought of split times, kilometers, lactate threshold, or your maximum heart rate.
As you continue doing fartlek, you will learn to run with the landscape; often natural stopping and starting points for the hard running will appear in the contours of the land. You might run hard up a hill and jog down the other side. Or you might sprint through a clearing until you reach the edge of the woods. If the trail disappears around a curve in front of you, run to the curve, recover until you get to the next curve, and then sprint again.
Where can you run a fartlek workout? True fartlek training should be done out away from town, says Bruce Gomez, track coach at Taos (New Mexico) High School. But any park will do, or even streets if nothing else is available. Give no thought to time or distance, or how many hard efforts you are putting in. Just run hard because you feel like running hard, sometimes longer, sometimes shorter. Mix it up and try to beat your training partner to the next tree or bridge. Run all out, run gently, run steady, run slowly, run strong, run uphill, run downhill, all in the same workout. "Most of all, run free," says Gomez.
And try this the next time you have a workout scheduled: Take off your watch and toss it on the floor. Kick it beneath your bed or throw it in a drawer. Close the drawer, go out the door and start running, just you, your shoes, and the landscape. Not only will running fartlek add longevity to your legs if you di it on a soft surface; running this workout with zest and élan in the true spirit of running can also add years to your mental health.
Consider wearing a shirt to help keep you free from structure on these workouts. We recommend "Fartlek: All sorts of running in one messy session."
In the Running Tough book, the long quotation above is followed by 16 pages of sample fartlek training workouts, which are more structured than what is described above, but which provide some good samples of what others have done with fartlek training. Again, we would highly recommend this book to serious or aspiring runners.
DISCLAIMER:
Persons choosing to utilize these sessions do so at their own risk. You agree to assume the risks of such training, and further agree to hold harmless Fartlekers from any and all claims, suits, losses, and/or related causes of actions and damages, including, but not limited to, such claims that may result from my injury or death, accidental or otherwise, during or arising in any way from copying and/or implementing these session suggestions. These session concepts have been offered as ideas for training, and are not intended to be followed without the approval of your physician.