Wesley Kiptoo has not just suddenly improved. He ran 22:54 8k last November at NJCAA champs and 13:43 5000m this February. He quadrupled at nationals, with 13:56/8:07/4:07/10:11 DMR. Where his improvement is remarkable is from where he started in 2018 and even from the end of track season in 2019 to Fall 2019 xc. Setting aside the Colorado Springs race, where he went 27, he dropped from 25:04 in September 2019 to 23:11 in October 2019. Maybe he was in such heavy training or even tempoing races that he was already getting toward that shape by the end of the summer in 2019. But maybe he improved so much because he hadn't been training very hard before. There actually is a history of Kenyans making enormous improvements at American colleges.
Sure but the evidence for that is zero. Who shows up and national championships in May of 2019 and runs 4:08/15:58. as tempo runs instead of winning the race?
Hey maybe he had some injuries or was only running 35mpw and the coach gave him a stern talking to at the of the season and he ran 90mpw for 12 weeks over the summer and that explains him running 23:00 8ks in the fall. It is possible. But go down the list of everyone who ran 4:02/14:48 type times between 2010-2018, and let me know how many of them ran 13:45 type races the following season. It is going to be a short list.