I calculated my age grading for this race. Age grading removes age from the "picture" so we can get a better idea of our performance for our actual age. Here are my age grades for two years, the second being after my blood clots that occurred two years ago.
My age 46, 17:44, 72.73% Year 1982
My age 75, 32:19, 39.92% Year 2011
The first number (after my age) is the time a runner would finish who was 25 but in the same condition for his age that I was for my age. The next number (a percentage) shows how close I was to reaching the world record for my age.
Now, we can see the help that age grading gives us. I calculated my age grading for an assumed age of 76 and an assumed time of 26:31. Guess what, my runner-friend at age 25 would have a time of 17:44 for both ages. That is, a 5K time of 26:31 at age 76 is the same as a time of 19:48 at age 46, even though 26:31 is no way near a PB of 19:47. Age grading allows me to compare times over a large time-span, in this case 29 years. Concerning my performance this morning, I'm about 21 minutes away from an all-time PB, taking my age into consideration. Rather than thinking I have to reach a time of 19:47 to set an all-time PB, I only have to reach a time of 26:31. Now, my performance this morning doesn't seem so bad, after all :)
As a side note: I've spoken of having blood clots two years ago. Actually, the blood clots were a side-effect. The real problem was a filter the doctors put in my vein after an auto accident in 2004. For about 4 years I had a great time running. Then in January 2009, the filter quit working, and it blocked the blood circulation in that vein. I went from a 7-mile run on Saturday to a 100-foot walk on Monday. New veins have grown around the filter, but my performance is still way below what it was a few years ago. But, that's OK. I'm still alive and still running, and it's a great life!