I call B.S. on 5k/8k conversion factors

Easily under 25:00

McMillan shows 24:43

Would you call BS on 15:00=31:15 10k?

If that’s fair, and there was a linear slow-down between 5 & 10k, then 15:00 (3:00/k) would equal 24:36 (3:04.5/k) would equal 31:15 (3:07.5/k).

Jamin, you were a math major right? "Conversions" are inherently faulty because they are an opinion, not empirical fact. It's one person's opinion of what one performance's relative value to to another in a different event, statistically If you take these conversions to mean that one thing predicts another, then you are an idiot of epic proportions.

the IAAF book International Metric Conversion Tables defines conversion as follows:

A conversion is an estimate of what a performance which has been measured in one system of measurements would have been if it had been measured in the other system."

the operative word in that is "estimate."

a conversion is only ever an estimate, and folk who want argue about how accurate an estimate is are missing the point.

if you don't think it's accurate enough then either use some other method or invent your own.

cheers.

How often do you see 8k races on the track?

I agree that a runner with a 5k PR of 15:00 on the track is unlikely to run 24:45 on an XC course.

The estimates from the conversion tables assume the same:

1. surface

2. conditions

3. optimality of training

For both races.

googler wrote:

The estimates from the conversion tables assume the same:

1. surface

2. conditions

3. optimality of training

For both races.

Would you cite your sources?

I recommend generating data in real time by actually running both events, then analyzing the results afterwards. Time is theoretically relative, but it’s unlikely that a runner would approach the speed of light (“c” in the famous theory), so the results could be estimated using purely Newtonian math.

BS + BS = BS wrote:

googler wrote:

The estimates from the conversion tables assume the same:

1. surface

2. conditions

3. optimality of training

For both races.

Would you cite your sources?

This is pretty obvious / standard across tables and calculators.

Says the guy who falls apart at races longer than 5K.

I had PRs of 15:03 for 5K and 24:36 for five miles, so the original conversion the OP mentions is more than possible.

ThatAverageRunner wrote:

BS + BS = BS wrote:

Would you cite your sources?

This is pretty obvious / standard across tables and calculators.

If it is obvious/standard then it should be easy for you to cite the sources.