About 20 years ago, I was at Dan Empfield's house and many of you do not know who he is, but he is very innovative, in many Hall of Fames, and designed the triathlon wetsuit and time trial bike. He is truly legend and outside of the box thinker. He is also a massive high school track and field fan. He laid out a line graph to show the progress of American boys 1600 and 3200 times over the years and decades. He dug for the most data he could get his hands on. For each year and decade he labelled them by what training shoes were offered by the major shoe companies. I do remember this...his data showed when heavy, higher heeled training shoes such at the thick Air Max with the dense and heavy EVA they used at the time were introduced, times slowed. I remember one trend over so many years where only 9 boys broke 9 in the 3200m. That happens most years in the "B" heat at Arcadia now. At that time, he attributed it to throwing mechanics off of runners and they shortened achilles tendons. He knew there was really no way to go back and get proper quantitative data, but there was a trend with such shoes. You guys have to understand, this is the way Dan thinks. As the heel height in such shoes started to drop, the times picked up again and with greater depth. I remember him using Alan Webb's timeframe in high school as a reference point to demonstrate not just his success, but the number of kids getting faster. Other reasons he attributed for slow times were the training and he is spot on for this one. In the coaching code at the time, very few coaches ran their athletes over 30-35 mpw and most of it had to be LSD (some of you do not even know what that is). And you were not to abuse your athletes and run few or any hard workouts out of season. I would say that has changed quite a bit. I have not spoken to him in years, but will try and track that graph down and post it. I fear it is in an Excel spreadsheet that will not open with more current versions.