https://medicalxpress.com/news/2025-02-female-runner-minute-mile-barrier.html

A recent study claimed that with optimal pacing, Faith Kipyegon could have broken 4 minutes. (Her actual time was 4 minutes, 7.64 seconds.)

Some races have pacers and wavelights to help runners break world records. That still counts as an official race.

"A controlled experiment" is meant to include conditions like what Eliud Kipchoge used to run a marathon in under two hours, which did not qualify as an official record.