I ran across this article from September's Running Times in another blog, Mission to A(nother) Marathon (as opposed to reading it in the actual magazine, which is somewhere in my house, probably at the bottom of some bag*). It's by running guru Greg McMillan (of the famous McMillan pace calculator), and distinguishes runners into three different types. You can go read the entire article (which also gives training tips for each type), or you can just read my spin on it here.
I should first caution that these running types really only apply to runners who care about their pace, whether they are trying to be competitive in races or just improve their own performance. I don't believe, though, that they only apply to the fastest runners. Someone could be a speedster (for example), whether their 5K time is sub-20 minutes or sub-25, or even sub-30. It's really a balancing of your running strengths and weaknesses rather than comparison of you with other runners.
The first category of runner is the speedster. The speedster likes and excels at short, fast runs (like track repeats) and short races like a 5K. Long runs, tempo runs, and long-distance races are not this runner's cup of tea. Even when he or she is well-trained and capable of the distance, the speedster cannot really transfer his or her speed to the longer distances.
The opposite of the speedster is the endurance monster. The endurance monster loves distance and performs well at it. This runner may find that his or her top pace in a half marathon or a marathon is not that different from his 5K or 10K pace! However, the endurance runner sucks at track workouts.
Finally, the versatile runner is, according to McMillan, the most common type of runner. This runner performs pretty much equally well at any distance (based on a curve). That is, her 5K pace is fastest, 10K slightly slower than that, and so forth. This is the type of person that running calculators work best for. However, even versatile runners usually have a tendency or preference toward either speed or endurance, which will be reflected in their race times.
So I can tell you what I am not, and that is a speedster! This line from the article's description of endurance monsters describes me to a T: "EM finds it very difficult to get her legs to go fast." My summer of speedwork has improved my speed and ability to go somewhat fast, but short, fast distances are not my preference.
However, I think that my recent months of training have made me into more of a "versatile runner" (albeit with tendencies toward endurance over speediness). I have improved my pace and PR's in all distances, but my 5K pace is now quite a bit faster than my half-marathon pace! And my comparative times for the various distances fit pretty well into the running calculator curves.
I took a small shot at speedster-ism this morning with my Wednesday morning track work. I did a long warm-up, 5.25 miles, so I only had time for four quarter-mile repeats (with a quarter-mile recovery jog between each). My primary goal was to do each quarter under 1:50, and my ultra-goal was to hit 1:45 (but I didn't know whether that was possible).
Here's how I did (laps two and four were .26 rather than .25 miles, which is reflected in the relative times and paces).
1 - 1:48 (7:19 pace)
2 - 1:49 (7:08 pace)
3 - 1:47 (7:12 pace)
4 - 1:45 (6:53 pace) - I did it! (And even better than planned, since this was one of the longer laps.)
After I finished I did another mile of recovery and running home, for a total distance of 8.01 miles. Final stats for 8.01 miles - 1:15:31, 9:25 average pace.
*I am aware that running snobs prefer the Running Times to Runner's World, but I am a bourgeois runner and I like the blatant middle-of-the-roadism of Runner's World, which I read avidly (Running Times I have a hard time getting into). (Though I do like the picture in this article. Maybe I should look a little closer....)