What are those blue sleeves worn by Sanya Richards?

Question

What are those blue sleeves worn by Sanya Richards?

Answer 1

It was something developed from Cathy Freeman's "Windsuit"

It's so your arms can cut the air cleanly

Answer 2

it's supposed to keep the skin and muscle from floppin around while you run which makes you slower. like it's the same with the swimming suits for the swimmers which are tight to keep everything compact and makes  you more dynamic

Answer 3

whatever it was it didn't make her FASTER...