Fartlek

Fartlek is a middle and long-distance runner's training approach developed in the late 1930s by Swedish Olympian Gösta Holmér. It has been described as a relatively unscientific blending of continuous training, with its steady pace of moderate-high intensity aerobic intensity, and interval training, with its “spacing of more intense exercise and rest intervals.” Simply stated, in its widely adapted contemporary forms, Fartlek training is alternating periods of faster and slower running, often over natural terrain, including both “level and hilly terrain.”
While Fartlek training is generally associated with running, it can be incorporated into almost any kind of exercise. The variable intensities and the continuous nature of the exercise stresses both the aerobic and anaerobic parts of the runner's physiology. It differs from traditional interval training by being less structured.
An example of its more modern manifestations in the training of serious runners is found in Mona Fartlek, named for Australian distance runner Steve Moneghetti, devised by Olympian Chris Wardlaw. This training style injects speed into a 20 minute session, pairing alternating periods of effort and recovery: 90 seconds on, 90 seconds off, then 60 seconds on-then-off, and 30 seconds on-then-off, and 15 seconds on-then-off, generally, with intensity increasing as the effort period shortens, with the specifics determined by coach and athlete.

Etymology

The term Fartlek comes from Swedish, Fart the word for speed, and Lek means play, and so “speed-play” It was originally written in upper case, although it now generally appears in lower case. It is otherwise known as the Swedish natural method or simply the Swedish method.

Modern definition and utility

Fartlek has been described as a “relatively unscientific blending” of
continuous training—whose forms include long slow distance training—with its steady pace of moderate-high intensity aerobic intensity and interval training, with its "spacing of exercise and rest intervals." Hence, in its widely adapted contemporary forms, Fartlek training can simply be described as alternating periods of faster and slower exercise, intermixed. In this adaptation of these other well-characterized training methods, the interplay between the effort and recovery are not systematically manipulated; instead, the athlete and coach determine the interplay "based on 'how it feels'" during the training. To some extent, in distinction to the earliest forms of Fartlek, its evolution has taken it further in directions away from the track, toward natural outdoor terrain, including both “level and hilly terrain.”
From the perspective of exercise physiology,

hen properly applied, overloads one or all of the energy systems... provides ideal general conditioning and off-season training strategies ... freedom and variety to workouts.

In relation to continuous and interval training methods, these same authors note that there is “nsufficient evidence ... proclaiming superiority of any specific training method to improve aerobic capacity and associated physiologic variables ... Each form of training produces success.” They go on to argue that, “ne can probably use the various training methods interchangeably, particularly to modify training and achieve a more psychologically pleasing exercise or training regimen.”

History

Gösta Holmér

coach Gösta Holmér developed Fartlek in the 1930s; since then, many runners and running coaches have adopted it. It was designed for the Swedish cross country running teams, which had been beaten throughout the 1920s by Paavo Nurmi and long time rivals the Finnish team. Holmér's new training plan applied a faster-than-race training pace and innovated by mixing speed work and stamina training into one session. Like interval training, it involves running at speeds far higher than normal for short periods. Where Fartlek differs from interval sessions is in the fact that these short bursts of pace occur within a continuous long run. The short, fast runs alternate with longer periods of easier running.

Early uses of Fartlek

In the late 1930s, the decade following Finnish runners' supremacy under Paavo Nurmi, Gosta Holmer was the national coach for Sweden, and he devised an approach that has been called as "innovative as any idea in athletics' history", introducing "faster-than-race-pace, simultaneous speed/endurance training" which he termed "Fartlek", meaning "speed play". In Holmér's hands, the sustainable speed of his runners was not achieved through Fartlek workouts alone; his training regimen included "epeat track workouts, tempo runs and time trials ... alternated or combined with Fartlek" through each training week. For his Swedish runners, which were world-class, the original Fartlek workout has been described as "a total of 12 kilometres running with up to 5,000 metres ... being at faster than race pace." Described by another, a typical workout might be "seven total miles of running with 4,000 or 5,000 meters worth of lickety-splits , from 40-meter sprints to upwards of 2,400-meter pick-ups".
Holmer used the technique on a forest loop where he instructed Gunder Haegg and Arne Anderson to run fast when the instinct moved them and slower to recover. He credited Fartlek as the reason they ran near 4:01 for the mile on various occasions.
Fartlek training was, by one account, introduced in the United States, in the 1940s. By the 1960s, in the hands of Doris Brown Heritage, an inductee of the Track and Field Hall of Fame and running coach at Seattle Pacific University, her Fartlek workouts had become assigned to 20-minute sessions beginning and ending with mile runs, between which were sandwiched an unstructured intermix of "40 to 200-yard sprints and five to seven minute segment 'perceived exertions'". In her university coaching, her cross country and track runners faced these, as well as "lots of short sprints ... five to seven minute runs".
At Portsea on the Australian shore, at a "rough and tumble training resort", Percy Cerutty had, through the 1950s and into the 1960s, applied forms of Fartlek focusing on the freedom of training variations it allowed; his forms were "deeper and steeper", involving "20 percent beach running in heavy sand, 10 percent repetitions up dunes ... and the remainder ... sprints, jogs and middle-distance runs" akin to those introduced by Holmér, which he led "along cliff top paths ... seashore and dirt roads." The work on the dunes was noteworthy in that some were "as high as and as steeply graded as the stairs up the Statue of Liberty". For Australian runners training at Portsea, which for some comprised half of their yearly schedules, the training was without any traditional, structured track work. In the early 1960s, innovative and highly regarded distance coaches such as New Zealander Arthur Lydiard adapted Holmér's training approach, and like Cerutty, introduced Fartlek-type workouts, again "over both flat and varied trails", using markers to indicate points at which sprint and middle-distance changes in pace were to be made. As described by Joe Rogers, who coached at Ball State University and West Point, "he Swedes used ... pine needle forest trails ... terrain training, and hilly Fartlek courses ... primarily, it was on level paths", whereas Lydiard used both flat and graded elements in his training: "On the flats, athletes changed paces at markers. The hill courses had built-in stressors."

Example session

This is the first session that was designed by Gösta Holmér for a cross-country runner. It is an example of what a Fartlek session might look like—although Fartlek sessions should be designed for an athlete's own event or sport, as well as catering to their individual needs.
According to this source, sessions should be at an intensity that causes the athlete to work at 60% to 80% of his or her maximum heart rate. This should mean that the body will not experience too much discomfort while exercising. An athlete should also include a good warm up at the beginning of the session, and a cool down at the end of the session, to improve performance, minimize post-workout muscle soreness, and decrease the chances of injury and for other reasons. An example of a training session is:

Warm up: easy running for 5 to 10 minutes.
1 minute on, 2 minutes off, alternating fast and easy pace
Cool down: 10 minutes at an easy pace
Fartlek variations

Major forms

Mona Fartlek

Australian distance runner Steve Moneghetti lends his nickname to a training workout "well known ... in Australia", which was "devised by his ... coach Chris Wardlaw ... a dual Olympian". The workout, which provides a "way to inject ... speed" into a run, has been described as a "cut-down ladder-Fartlek", and was a track workout in its original design but is suited to any continuous course. The workout was designed to fit a 20-minute session, accompanied by a requisite warmup and cooldown, e.g., of half the training length. It pairs periods of effort and recovery, specifically consisting of two 90-second efforts, with the same pattern then being followed for four efforts of 60 seconds, four efforts of 30 seconds, and four efforts of 15 seconds. A stated assumption of the workout is that as the period of effort shortens, the intensity of the effort increases, although actual workouts are tailored to individual runners' needs. In one description of the workout, beginning pace during the effort portions is intended to fall about at the runners "5K pace", with subsequent shorter intervals being taken at faster pace as the runner is able, and with recoveries varying from walking and easy jogging for newer and other runners needing "more recovery between hard efforts", to half-marathon/marathon "race pace recovery" or 5K/10K race pace "moderate recovery" for more experienced runners. In more sophisticated presentations, the workout is adapted to particular periods of a runner's "training year":

or example ... in a base building period ... the efforts remain completely aerobic, but very near the top of the anaerobic threshold. The recoveries are floats, rather than easy jogging. During this , the run more resembles a tempo run with a higher level of intensity than what a tempo effort in one strong effort can typically offer. During the quality of training, the recoveries can be a jog, while the efforts delve into the anaerobic realm. The efforts should be done by feel and can range in ... pace from 1500m ... to 10k race pace, again depending on the time of year.