The year: 1984 & the USA had 165 Sub-2:20 performances

smnfdkohj wrote:

I entered each year, the avg. number of high schoolers plus the number of sub 4:10 milers and sub 9:00 two milers. Ran a correlation and found a correlation of .669 for population and sub 4:10. I also found a correlation of .763 between the two mile and population.

This doesn't necessary prove that population influenced the number of fast times, but it does show that as population increases times get faster and vice-versa.

That was summed up here:

1970s:

12,299,000 average HS aged children each year.

3,887,352 participants in all sports (boys)

105 4:10 milers

102 9:00 2-milers

Lets compare the other decades.

1980s:

10,780,000 HS kids (-12.4%)

3,387,482 participants (-12.9%)

68 4:10 milers (-35.2%)

49 9:00 2-milers (-52.0%)

1990s:

11,111,000 HS kids (-9.7%)

3,605,942 participants (-7.2%)

38 4:10 milers (-63.8%)

17 9:00 2-milers (-83.3%)

malmo- where do you get all these figures? you are a wealth of information. now, we argued on another thread, but i commend you for your vast knowledge, or at least access, to all the stuff you post. do you put this info to use to assist in developing our youth runners, or just commentating on the state of affairs, just wondering. as an exercise science guy/coach/parent, interested in knowing. thanks.

terps wrote:

now, we argued on another thread,

"WE" haven't argued. You have. I just present facts for those how want to discuss them, provide my analysis earned from decades of experience as both an athlete and a fan.

You should realize that the information in this thread is a very old one. You should click on this link to get some more background on the high school miler/2 miler thread.

NFHS refers to some high school federation. If you want the original study, I believe it might still be available in pdf form on the website. good luck.

back then there were guys like doug kurtis who seemed to run sub 220 every month, and people ran marathons as part of their buildup and as training runs, now everyone seems to think more than 2 marathons in 1 year will ruin you forever, there are some exceptions like mary akor who seems to run a marathon every few weeks, but where are the guys like doug kurtis and kjell erik stahl (of sweden).

Yeah, but you told me my numbers didn't "jibe". I'm saying that according to Pearson correlation, my numbers do "jibe".

smnfdkohj wrote:

Yeah, but you told me my numbers didn't "jibe". I'm saying that according to Pearson correlation, my numbers do "jibe".

What does the R Value have to do with anything? On the first day of your statistics class someone should have told you "correlation does not imply causation." Without running the calculations and just by looking at the tables I could have told you that the R Values were going to be in the .6 to .8 range. So what? Just by looking at the summary table and without doing the calculations I could have told you that the 2mile results will have a higher correlation to population than the 1 mile. So what?

Without doing the calculations I could tell you that the R Values of arrays {80s-90s population}{80s-90sresults} is going to be well under .6, perhaps close to zero. Again, So what?

Without even looking at any data I could have told you that the number of sub 4:10/9:00 performances is dependent on population. But changes in population don't cause changes in performance any more than changes in 4:10/9:00 performances cause changes in population. Get it? The only thing that the R Value tells you if that population changes the dependent variable is going to change to some proportional degree. That's common sense. If a population data set is 5.0 million (as compared to 11 or 12 million) the number of sub 4:10/9:00 will change by a large degree. No kidding? That's what a high correlation (R-Value) tells you, but it's an almost meaningless statistic to know.

The important relationship that is obvious from the above table, is that a small drop in high school population resulted in a huge drop in sub 4:10/9:00 performances (especially the 2 mile) in the 80s and even more so in the 90s. The next most obvious relationship observed is that the population increased from the 80s to the 90s yet the number of 4:10/9:00 continued to drop.[/quote]

Thanks.

[/quote]

Without even looking at any data I could have told you that the number of sub 4:10/9:00 performances is dependent on population. [/quote]

You're welcome.

smnfdkohj wrote:

I am completely convinced that the difference is caused by the Baby Boom generation!

malmo wrote:

The facts don't jibe with your thesis.

"Correlation doesn't imply causation"

only 3 americans so far under 218 according to iaaf.org and 8 under 220 according to trackand fieldnews.com, but fear not, look for at least 1 in the san diego marathon on june 3rd a couple more on june 16th in minnesota, 5 more at worlds on august 25th and some more in chicago and minnesota on october 7th, i heard there is a 25 k prize to the first american masters runner then a whole bunch will go sub 220 on november 3rd as 158 are qualified to run according to usatf.org i say we get 50-75 under 220 this year mostly because on the trials on november 3rd.

yep