Just one more on marathons, since I know not everyone is interested. On calling out times, US runners are used to calculating their approximate, and hopeful, finish times by multiplying the cumulative per mile time by 25 and then adding one more (marathon is about 26.2 mi). Thus, if the most recent cumulative pace was 9:30, a runer would think:
"25 x 10 is 250, less 25 x :30 is about 12, plus 10 makes about 248 or 250 minutes, which is about a 4:10 finishing time." If we switch to SI, the multiplying is no longer by roughly 25, but 42 or maybe 40, which may be a lot more difficult mentally. It becomes HARD to do these calculations after running about 30 km and really tired and all you can think about is when you can go home and have a hot shower and maybe some aspirin! I guess we could use 2 km intervals and multiply by 20 as a basic calculation. For 10 km races, which are a lot more numerous, calling out a single time at the 1 km mark makes a lot of sense, since all you do is multiply by 10. This is what I have been trying to promote. HARRY WYETH
