>>1312298Poles yes for steep ascents and snow fields, provided you know how to use them. Running poles are light and can be collapsed or deployed while running.
Hydration pack yes, get one that has everything you'll need accessible without taking it off. Filling a bladder at an aid station is a waste of time. Go for chest-mounted bottles instead.
Do lots of stability exercises to strengthen your ankles. You will snap them otherwise. Also core strength.
Work on your downhill technique. Most people are useless at it. It's an easy way to get a better ranking. Helps your knees too.
Practice pacing. Learn how fast you can go over what terrain. Factor in steepness, temperature, weather, nature of the trail (mud, snow, gravel, hard-pack, ridges, scrambling, ...).
Don't start too fast. Most people will do so. They are wrong and regret it soon after. Chances are your body can't cope with the rapid build up of lactic acid.
Learn what you and how much you can eat under what conditions. Try gels, bars, salt pills, whatever.
90% of your training should be done at low intensity.
No experiments on race day. Try everything in training.
