I have noticed that some Kenyan athletes have a forward lean at the hips, much more so than US athletes that run very upright. I have also noticed that Jakob Ingebrigsten, the brother of Filip and Henrik Ingebrigsten, has a forward lean, unlike his brothers. He is also notably faster than his brothers. You could argue it's due to their teaching and advice, but it seems to stand out. To add, Matthew Centrowitz also has a less prominent lean but you can still tell. Any science behind this? I know many sprinters are upright when they hit their top speeds but what about distance runners??