I always think that sport specific training is interesting because some individuals who begin training for a specific sport will neglect some parts of their body while focusing solely on other parts. The reality is that all athletes should be well balanced and have a similar training base of exercises. An athlete can never go wrong by including squat, bench press / push-ups, Lat pull / pull ups.

BUILD YOUR ABS/CORE
However, going beyond developing a good training base it is important to evaluate the actions performed in a sport and how these actions are performed. When we look at snowboarding we will see like in all sports that movements are performed in all three planes (sagittal, frontal, and transverse) and a large of amount of movements performed in the transverse plane due to the large amount of trunk/torso rotation. Due to the fact that there is so much movement and stabilization in the transverse plane it is important to train you core well and in particular your External obliques. Two great exercises for training your external obliques are ab crunches with a twist and abdominal rainbows.


BUILD YOUR QUADS
In addition to training your core it is also very important to train your lower body. As you're snowboarding down the mountain your legs are continuously engaged, particularly your quadriceps. This makes building up your quads very important and squats are the best exercise to train these and it mimics the actions of snowboarding very well. Also, since you will be riding down the mountain and holding a semi-squat position then performing an isometric squat will be very helpful. So, I'd recommend using a stability ball to lean up against a wall and hold squatting stances for 30 to 60 seconds at various angles.

BUILD YOUR CALF/LOWER LEG MUSCLES
When snowboarding you will perform lots of cutting as you change direction and go back and forth along the runs. When you perform these cuts you will engage the muscles of your lower legs that help you plantar flex and dorsi flex your foot. So, building up your calf muscles are very important, both the Gastrocnemious heads and the Soleus. When your perform any calf exercise you perform will work both the Gastrocnemious and the Soleus. However, performing a calf exercise like a seated calf exercise will work the Soleus more which is engaged quite often during snowboarding because you are in a semi-seated position quite often.

In addition to working your calf muscles (plantar flexors) it is also very important to train your dorsi flexors. The major dorsi flexor of the foot is the Tibialis anterior. You can work this and the other dorsi flexor muscles of the foot by attaching an elastic band to the top of your foot and a then attaching the other end of the band to something away from your and plantar flexing your foot and then trying to bring your toes towards your body.

Well, I think this is all i can write for now, but this should be a good start. Also, I should mention that snowboarding is a very explosive type of sport and plyometrics would be a helpful part of your training.

I will soon write up a training program for this and post a link in this forum to it.

This program should be up in the next couple of weeks.