Yep – all good advice above. I think training is difficult as there’s just nothing quite like it. Obviously overall CV fitness will help but nothing can prepare you for 1-2 hours of full on downhilling.
My advice would be just don’t take it too seriously. The qualifier is great fun and a bit more downhill orientated (dirtyrider – you must’ve been in the same final as me this year – what row were you in?). The mega itself is just insane, especially with the amount of snow we had – trying to ride the top section leaves you in no doubt that it’s an endurance race rather than full on DH. Bigger bikes are more fun for the qualifier but a suitabley beefed up 5-6″ travel bike is perfect for the main event – there’s enough flat/uphill to make a DH bike a slog (3 of our guys were on Fives and rode them rather than their DH bikes; I rode a 120mm Mount Vision).
Just go there planning on having fun – the atmosphere, course, surroundings and other riders are all amazing (it’s not often you can chat to multiple World Champs on the start line of a race 🙂 )
Edit – a CCDB would be sweet I reckon. One of our riders has an Alpine with one on and loved it