Thank you!! dont know why people always tell you to lift weights. You don't need heavy ass weights to snowboard you'll get big, heavy and slow. Now light weight training could help, but concentrate on doing cardio lots of it since you will need as much stamina as possible. work on your core(midsection), legs and back(lower). try to be as flexible as possible.
First off, I agree with most of you that spending a lot of time weight training will not be nearly as beneficial as endurance/core/balance training. I would like to clear up some misconceptions though.
Getting big and heavy will not make you slow. It will make you Fast as F
ck (reducing quickness and manuverability for tricks however).
Heavy Ass Weights is a relative term. Muscle fibers are recruited in order by size. First the Type I fibers (slow twitch / endurance), then as load increases Type II a & b (fast twitch / power) are used. The latter do not fully come into play until (1) your slow twitch fibers tire out, like the last few reps of a set, or (2) when using about 90% of maximal effort, like heavy squats, box jumps, or something explosive. If you never train around the 85+ % effort range, you will be far less explosive off of jumps, etc than your potential.
Lifting in the 85+ % effort range would be a weight you could probably do 5 or fewer times. Lifting in this range trains your central nervous system to recruit all muscle fiber types at once. This makes your body much more efficient at using the muscle it already has
. Training in this range also causes the body to grow more contractile protiens (actin and myosin) which make you stronger.
Lifting in the mid-rep range (10-12 reps), like bodybuilders, causes you to grow more muscle mass, but less contractile protiens (aka funtionless size). This is part of the reason you see many 225 lb bodybuilders that can only bench in the mid 300lb range but 225 lb powerlifters can lift in the upper 400 lb range or more (even though the power lifter has a higher bodyfat %, which means less actual muscle mass) (it also has to do with knowledge of proper form and leverage).
In summary, lifting heavy weights will condition your nervous system to be more efficient and build useful muscle. As long as you follow a healthy diet you don't have to put a ton of size on.
Food for thought young grasshoppers