Road Running Records

Recently I pulled together an interesting (to me) chart of my personal best road race record times at various standard distances, with a column for pace in minutes/mile and with the second-best results also included:

Distance PB year pace 2nd year
1 mile 6:3120096.66:332011
2 mi 13:4120096.913:522010
5 km 21:5420107.122:152009
8 km 37:5120117.648:432002
5 mi 41:5120088.444:402007
10 km 46:5720097.647:072012
10 mi 1:18:0020127.81:18:412012
1/2 mara 1:55:3320098.91:57:482011
marathon 3:58:1520129.14:01:062009

Eyeballing it, clearly I've badly neglected 5 miles over the years and have only run 8 km (= ~4.95 miles) seriously one time. Graphing the pace values versus distance on a log scale is even more revealing:

Half a dozen of the dots form a nice almost-straight line of records from 1 mile through 10 km. On the average, every time the distance doubles, my pace slows by about 0.3 min/mi. But those top three points are the anomalies, at 5 miles, the half marathon, and the marathon. Can they be pulled down to that same trend line, by more disciplined training, more mental toughness, etc.?

(cf. SpeedUpSlowDown (2004-10-18), Running2006Analysis (2007-01-27), Year of Running - 2009 - Further Observations (2010-02-01), ...) - ^z - 2012-04-16