Just saw Braxton retweet this today.
http://ftw.usatoday.com/2016/02/exclusive-adidas-offers-1-million-to-nfl...
I know he said that he wants to run sub 4.4, but that would be a long shot to take Chris Johnson's record. Plus, you have to wear Adidas shoes in order to be eligible for the prize, and Boobie Miles says you've "Gotta knock em' out in Nikes", so we all know that's not going to happen.