Just saw the top 5 HS list for 1500m on the 10 article, and I said what the heck why were the top 4 all run between 2013-2016? I like my theory that people are faster now largely due to cultural changes, and like 1-2s/mile maybe due to better spikes. This would fit nicely into that, because Mary Cain would've been the super-talent that brought out the best in her competition, and a couple years later the biggest talents would be shooting for her marks (Efraimson, who in turn inspired Aragon/Murphy). Similar to how Newbury Park inspired a bunch of HS guys to raise their level (4:20 isn't fast mindset), with Nico leading the way for his teammates, who in turn raised the bar for the people their age. Also similar to Cheruiyot running 3:29 to win WCs, Jakob running 3:28 to win the Olympics, and then suddenly all the top guys are running sub-3:30, and the 2 most recent world champs said they specifically changed their training to be able to run championship races in under 3:30.
That leaves a question though: Why aren't HS girls running anywhere near as fast as they used to in the 1500? My best cultural guess is because Tuohy showed up in 2016 or 2017 and was better at 3k/5k, so other big talents have followed her lead. 15:37 was a super strong record, but it's been broken twice since then, while it's been 8 years since any girls broke 4:09. Otherwise idk maybe the shoes save your legs more when you're training for 5ks so you have more of an advantage? Although I think either Cook or Hutchins did a ton of cross training and not much running, so idk how much it'd have helped them.
Disclaimer I could be totally wrong I have literally 0 idea what was happening in HS running before 2019. Maybe everyone just decided they didn't like 1500s and only ran miles idk.
List for reference
4:03.39 Alexa Efraimson, 2015
4:04.62 Mary Cain, 2013
4:07.21 Kate Murphy, 2016
4:08.71 Christina Aragon, 2016
4:09.70 Sadie Engelhardt, 2024