In the 1940's, Swedish coach Gosta Holmer created a new type of training which was called fartlek ("speed play" in English). It was first described in English in a series of articles in Sports Illustrated. Either there was trouble with translation or an inability to express ideas clearly, but I've read them and got nothing out of them. Apparently, that was common reaction, as fartlek has now devolved to mean any non-structured speed workout not done on a track.
Typically, coaches have runners do fartlek as a break from running on a track. Athletes get to associate tracks with grueling workouts and mind-numbingly sterile terrain. When they seem to be burning out, coaches then send the runners into the woods with instructions to run fast when they feel like it and the runners come back refreshed from the change in scenery and getting away from the stopwatch. Unfortunately, some runners turn these runs into too hard workouts and others just go for a slow jog with a couple of short bursts of speed for show. (This has been derogatively termed "American fartlek." Worse, there's "Lydiard fartlek" which is a fast continuous run done with the last mile or two faster than the others; it's a good workout with an unfortunate name.)
I think what Holmer was trying to do was to do to interval running what the Finns had done with continuous runs. If one thinks of intervals as weight training for the heart, then doing them on difficult terrain would be like using heavier weights.
If one uses the assembly line approach to intervals, then one can divide a trail run into its components by type of terrain. One then runs multiple loops of a short course, emphasizing one component, whether it be running hard downhill or running hard through sand. This has been modified by most runners due to lack of an appropriate course to doing hill repeats. Those who run short trail races often train to run hard uphill, as they need to be able to do that in races; conversely, those who do ultramarathons on trails often walk uphill and run downhill, as this approximates the attempt to run at an even effort in races (and strengthens the muscles that tend to fatigue first in these races).
There was a new approach to fartlek, first done in Poland (and thus I learned of it as "Polish fartlek"), called timed interval fartlek. Over time, it became standard for coaches having runners doing an "anaerobic threshold" workout have their hard and slow segments done in a 1:1 time ratio and their "maximal oxygen uptake" workouts done 2:1 (rests half as long as the hard bits). This, then, became a way to run away from the track, alternating 3 minutes hard and 3 minutes easy or 4 minutes hard and 2 easy. By doing these workouts on trails, sometimes the hard sections would be uphill, sometimes downhill, and one theoretically learned how to run hard under any circumstance.
In my own case, I found that I could base these workouts on heart rate and use a monitor that would alert me when my heart rate was not in a specific zone. I'd then use the workouts I specified at the end of the last post and, if I didn't have a good handle on my current fitness, would just assume 85% effort was 85% maximum heart rate, which is for me a fair first estimate. As a joke, due to the amount of math done on an old HP calculator to figure out these workouts, I referred to these as Reverse Polish fartlek (middle-aged nerds will get the reference).
Having described how I train - and thoroughly bewildering anyone who's still reading - the next posts will be on racing, rather than training.
6 hours ago