Not everyone, but at least someone. If I'm to believe that it works for everyone, regardless of talent, where were the Boulami, Mourhit, and Ramzi performances by non-African heritage athletes? I've been shown many things that do not address why there are so few quality examples from athletes that are not East or North African heritage. Why does anyone seriously struggle with "at the top"? Go to any list like "alltime-athletics" -- the times at the top are faster, better, worth more. The value is not binary YES or NO, according to some arbitrary cutoff subject to useless debate, but increases and decreases inversely to the position on that list. As you go down the list, the relative worth decreases as the times and ranking gets bigger, becoming worth less, then worthless. The actual cutoff representing the bottom of the top doesn't matter. VO2max? Give me a break -- why pick a metric not often measured, not reliably measured, and only loosely correlated to performance? No, not VO2max.