Training for a 20K Race
The 20K is one of my favorite events. It is a challenging distance that is not for the casual weekend runner and requires a sustained training approach with an adequate mileage base. Unfortunately, the distance had pretty much disappeared from the DC racing calendar until the folks at the Leesburg 10K race added a 20K event to their August 8, 2004, 10K race. For those of us who used to run the Bethesda Chase in the 1980s and '90s, the Leesburg 20K offers the opportunity to renew our love affair with that distance. For those training for the fall marathon, it can be a substitute for your long run, could be used as a marathon pace workout, or, if raced all out, a benchmark of your fitness level that can help assess your fall marathon goal pace.

A 20K training program should, at a minimum, incorporate the following ingredients: a long run, a mileage base of 20 to 25 miles per week, and anaerobic threshold speed work. In addition, racing a 20K involves a completely different strategy than one would use in a 10K race.

The Long Run
It is recommended that you do a weekly long run of at least eight to ten miles in preparing for the 20K. A weekly run of twelve to fourteen miles is optimal, meaning that, unlike the marathon, the weekly long run is the same distance as the 20K or even slightly longer. The run should be done at a sixty to seventy-five percent effort using your heart monitor, or at an easy conversational pace. This weekly long run accomplishes several purposes, including helping the runner get used to the distance and the heat as well as building leg strength. Runners need to stay hydrated, especially during the summer, and may want to practice drinking on the run to simulate race conditions. As you are peaking for a 20K race, you may want to throw in a few miles at projected race pace during the middle or end of the run to learn the feeling of that effort while fatigued.

Weekly Mileage
The 20K race is more than twelve miles in total and is about three-quarters of a mile short of a half marathon. It takes a fair amount of leg strength to complete that distance, especially if you want to stay injury free. Thus, I recommend that runners average at least 20 to 25 miles per week if they are thinking about racing a 20K. A mileage base of 30 to 35 miles is even better. Of course, if you are doing the long run as suggested above, you will already be at about thirty to fifty percent of your goal. Most of this mileage base will be done at a conversational pace, sixty to seventy percent effort. Keep in mind that each mile that you run will make it that much easier to complete the race.

Anaerobic Threshold Speed Work
The best bang for your buck in terms of speed work for the 20K distance (and the marathon as well) is anaerobic threshold (AT) pace training. My two favorite AT workouts are three times one mile at eighty to eighty-five percent effort on the heart monitor, or a few seconds per mile slower than current 10K race pace and a twenty-minute continuous AT run. When doing three times one mile, recovery should be one to three minutes between miles. If you need to recover longer than that, you are doing the miles too fast. Your goal is not to run the miles as fast as possible, which I know you can do, but at the risk of injury. If you do the twenty-minute AT workout, you will notice on your heart monitor that you are slowing down at the end. That is okay because you are still running at AT pace. It is more difficult to do a twenty-minute AT run without a monitor because you have to do it by a sense of effort. You should feel on the edge during the entire twenty minutes, i.e., you are going very hard and if you picked it up a bit, you would want to stop. However, within twenty minutes of completing the workout, you will feel terrific.

Racing the 20K
Your 20K race pace will be 15 to 30 seconds per mile slower than 10K race pace. If you are doing the Leesburg 20K and it is hot and humid, you may want to think about running even slower to avoid heat-related problems. If you go out too fast in a 20K, you may face ten or eleven miles of pure agony trying to complete the race. If you are not sure about your pace, I suggest that you go out pretty easy to ensure that you are not breathing too hard. Once you pass the first mile marker, you can assess your race pace and conditions to determine whether you need to pick up the pace. Your level of effort in a 20K is pretty hard but you should be able to say a few words at a race pace, unlike a 5K or 10K race where you are literally speechless if racing all out.

A final word of caution: If you are a casual weekend runner who does one or two 10Ks per year, I strongly urge you to resist the temptation of trying to do the 20K race. Stick with the 10K race because you know that you can finish that distance, and save the 20K for next year when you have a chance to properly train for it.

Coach Kirt West is a private coach for motivated adult runners. Questions can be sent to him at kirtwest@comcast.net.