PBs Ignore AgeThe problem with using PBs as indicators of ones performance is that runners slow down as they get older, and the time comes when a person is not physically able to run as fast as he or she used to run. Thus, comparisons of current times with PBs only have value when the PBs were recorded within a few years of each other. The number of years that comprise "a few years" varies with each individual, and this complicates the use of PBs even more.
Age Grading to the RescueIt would be nice if a way of comparing performance could be found that would be independent of the age difference between the times being compared. For example my PB for a 5K was made when I was 46, and the time was 19:45. I'm now 74, and I think it would be physically impossible for me to run a 5K in 19:45. Thus, that PB has no meaning today as a metric of my ability to run a fast 5K, and I list my 5K PB as 30:43, a time that was made three years ago. Even that PB is fading into the past, and within a few years I'll have to establish another PB.
I was pleased to recently learn about Age Grading, a method of comparing performance over any number of years. Through Age Grading, I'm now able to compare my running, whether I'm comparing my running today with that at age 46, or today with any point in the future.
Age Grading does two things. First, it transforms my race-times to the approximate times I would have run the distance when I was in my "prime", that is, in my 20s and early 30s. This means I can compare my "prime" times of races as a way of comparing my performance in the two races. Second, a number or grade is given that represents my performance, and I can compare my grades for the races, regardless of how many years have elapsed between the races. In other words, Age Grading accounts for my natural slowing down as I get older.
My Age GradingAs a real example of Age Grading, let me give the numbers for the two 5K races for which I have PBs, age 46 and age 71 (3 years ago).
Notice the differences in my "prime" time for the two ages. When I ran the 5K at age 46, my "prime" time was 18:12. When I ran the 5K at age 71, my "prime" time was 22:20. This means that in the 25 years that followed my run at age 46, my "prime" time for the 5K slowed 4:08, and my grade decreased by 13.242.
I'm 74 now. Suppose that in two years and a lot of training, I run a 5K in 26:46. As is shown in the table given above, my "prime" would be 18:12, the same as it was at age 46. Running a 26:46 at age 76 is the same as running a 19:45 at age 46. Is it feasible for me to run that fast at age 76? Yes, difficult but feasible. Such is the power of Age Grading in helping me understand my body condition now as compared to any race in the past or in the future.
I now have two numbers that I can use to gage my conditioning in the future: my "prime" time for the 5K and my grade for the 5K. If, as I get older, I'm able to decrease my "prime" time and increase my grade, I will actually be getting stronger as I age. Time will tell how the numbers change as I get older! I'm betting my "prime" time will go down and my grade will go up!