## Thursday, April 2, 2009

### More 5k Predictions

My linear regression of my bests predicts a 5K of 19:47. I haven't been sure what the function is supposed to be. Linear seemed okay. Online race finish time calculators seem so suggest longer times, though. I think what's most interesting is that my longer runs predict longer 5K times. It's hard to say whether I should be able to run those long ones faster, or if the functions used by these calculators just aren't made to apply to such distances. It's also interesting that my 5.25er predicts a slower time than my 7.5er. It makes sense, since the 5.25 is run as an interval workout, so is a less efficient way of covering the distance. Steady's better. Clearly, at least the Runner's Web one doesn't take into account the glycogen depletion threshold at around the 20th mile. I had been looking forward to possibly breaking 20, but it looks like I may need to adjust my expectations. The heat's going to be a bother, too. All my bests were run at ideal temps.

Runners World Calculator:
For a 6 min miler, a 6:38 pace for 5K means a 20:36 finish time.
For a 38:19 5.25er, a 7:04 pace means a 21:55 finish time.
For a 54:41 7.5 miler, a 6:55 pace means a 21:28 finish time.
For a 2:14:47 16.2 miler, a 7:31 pace means a 23:19 finish time.

Runners Web Calculator:
[ using T2 = T1 x (D2/D1)^1.07]
Using the mile, 20:18.
Using the 5.25er, 21:51.
Using the 7.5er, 21:18.
Using the 16.2er, 23:05.

Well, I guess I should expect something in the 21's. It's like 2 minutes slower than what I had been aspiring for, but I can live with that. I'll be happy if it's below 23. Oh man, the weather... I don't know how much of a wrench that'll throw in my plans.

// Weather update: it'll be "feels like 41" - sweet! I should be perfect in shorts and a tee. I'll go for tight clothes to reduce drag. Race conditions will mean slowing down because of traffic, but going faster due to drafting and adrenaline. There will be eastward 19mph winds, though, which means the last leg of the first loop and the last leg of the loop right before the final stretch will be a bit slower, since that leg (which we go over twice), is westward. 19mph is pretty substantial.

I'll think about taking a bit of caffine (new studies show its good effect on performance), and I may bring music (studies also show its benefit). I probably will wear the Garmin to track my pace. I don't know... it's heavy. We'll see.