Everyone in America has heard of Ken Roczen, the 15-year-old wunderkind of the Grand Prix circuit. Now here's a look at his rival, the even younger (by six months) Jeffrey Herlings, a KTM factory rider from Holland. This video was posted by Motocross Planet of Herlings working out on a sand track in Holland:

http://www.motocrossplanet.com/nieuws/item.php?nieuws_id=2754&home=1