Most serious runners realize that some timed interval work on the track helps build the speed that is necessary for top performance. I have found that most uncoached runners have only a haphazard idea about how to do this. They typically go to the track once a week or so, and "do some 400s" or 800s or 1200s as fast as they can. The next week they change the distance, and so on. The pattern of workouts is generally very repetitive, and there is no clear progression throughout the season. That is not the way to get the most out of interval training.

To extract the greatest benefit, it is essential to have a progression. To give an idea about how this works, let us imagine a 10K runner with a recent best of 37:30 (6:00 per 1600 meters), who wishes to run one interval workout per week. I will assume that this runner has already established a solid endurance base (at least 12 weeks emphasizing top mileage in the last year), because that is essential before starting any interval training. For most runners, the correct amount of fast running per interval workout will be between 2400 meters and 4800 meters, depending upon the level of experience.

The idea behind the interval progression is to run a variety of paces, while gradually increasing the pace as time goes by. The goal of each workout is to work a particular pace, adjusting the distance to provide a challenging (but not too challenging!) workout. The progression of base paces would look something like this:


Week 1 Base pace per 1600 = 105% of best (6:18)
Week 2 Base = 104% (6:14)
Week 3 Repeat base (6:14)
Week 4 Base = 103% (6:10)
Week 5 Base = 102% (6:07)
Week 6 Repeat base (6:07)
Week 7 Base = 101% (6:03)


and so on, until the base pace has reached 95% (5:42). Within the cycle, the runner may run workouts according to the cycle (base pace, base - 5%, base - 10%, base - 15%), providing variety in paces, within the overall progression. For this runner, the workouts would be:


Week 1 105% = 6:18, 1200s
Week 2 99% = 5:56, 800s
Week 3 94% = 5:38, 600s
Week 4 88% = 5:16, 300s
Week 5 102% = 6:07,
adjust distance based on week 1 results
Week 6 97% = 5:49,
adjust distance based on week 2 results
Week 7 91% = 5:27,
adjust distance based on week 3 results


and so on. Notice that although there is a rapid progression of paces within each cycle, the overall progression proceeds slowly. The idea is that for each workout at a given percentage below base (e.g., base - 5%), the runner should be able to do the same distances that the runner did in the previous cycle, even though the pace is a little bit faster (compare Week 2 to Week 6, or Week 3 to Week 7).

There are a few important things to note. First, the weekly interval workout should be skipped the week before a race (it's OK to still go to the track, even a couple of times, but the workouts should be much shorter, and completely relaxed). Second, distance runners should not stop and walk between repetitions, but rather should jog 400 meters or an amount equal to the distance run, whichever is less. Third, after a few weeks it is good to mix in some acceleration workouts (an example is running the second half of each repetition ten percent faster than the second half). After about eight weeks of interval workouts it is good to also mix in some step-downs, with full rest (including walking) in between. A typical step-down workout would be (base, base - 5%, base - 10%, base - 15%) with the faster repetitions done at shorter distances.

From a physiological standpoint, the emphasis in this interval progression moves from VO2 max (oxygen burning capacity) and lactate threshold (ability to use oxygen at high speed rather than muscle glycogen) to anaerobic capacity, muscular strength, and speed. Truly intense anaerobic work, of the sort the uneducated runner does every week by hammering the weekly interval workout, is used sparingly in this program, and only to provide the "icing on the cake."

It is a good idea to add a tempo run (a sustained run slower than the track repetitions and at least 15 seconds per mile slower than race pace) each week. These runs should not be anaerobic (they should not hurt too much or cause you to breathe too hard). Runners with several years of interval running experience can benefit from two weekly interval sessions rather than just one, but these runners should never run two interval workouts the week after a race, and should never run any hard interval workouts the week before a race. Many runners run interval workouts that involve more than 4800 meters of fast running, but based on my experience these should be avoided. Such workouts tend to emphasize lactate threshold more than VO2 max or speed, and there are safer ways (e.g., tempo runs, or pickups at the end of runs) to work on lactate threshold, without the unnecessary stress of running turns.

If you will add some structure to your interval training, you will be pleased to find that this progressive approach makes you faster and stronger, and that your times will improve as the season goes on.

Roland Rust coaches a handful of dedicated runners. (His coaching and running resume can be found at Resume.)

Roland can be contacted at rrust9@comcast.net .