im 14 too but not trying to kill my self doing jumps
Yes its a big part for me cos i race most weekends and if you clear the jumps you dont get as tired due to smooth landing and gain lots of time over guys who dont, also starts are much easier on the 450`s IMO
PS Iv broke many bones learning to jump the 80ft + tho as when it goes wrong its not very forgiving,,
EDIT: just seen the vid and i wish we had somewhere like that to practice cos most places in uk are tracks or police dont let you ride there