I like the exercise science studies that Kneesovertoesguy has done himself.
Like the highest jumper has awesome ankle dorsiflexion, the fastest guy has strong hip flexors and dudes with great longevity in sports can do Glute/Ham raises.
Unfortunately, observations are not studies. There is a reason why peer review, systematic review and data analysis are integral components of health research. Without them, “facts” are easily skewed