Before you arrive at the high altitude venue, be sure to consume a lot of water. You lose a considerably higher amount of water at elevation.
It would be wise to train with a heart rate monitor at all times, especially while at elevation. You will see a dramatic increase in heart rate while at elevation. Until you become fully acclimated (which can take weeks) make sure that you are primarily skiing easy. Intensity at elevation before acclimation (nice rhyme?!) can put you in a hole physiologically that can take months to recover from. Keep it easy for a long time. Live by your heart rate and even if it “feels” like you should be going faster, your heart rate will not lie.
As far as food goes, you will be burning more calories due to the extra exertion. We wouldn’t force feed ourselves in anticipation of needing to eat more. Keep it simple and eat until you are full! If you already have a pre-race meal that works for you at lower elevation, we would stick with that same meal at elevation. It would be a risk to change something that already works.
We reached out to Karl Nygren, to get his thoughts on altitude racing. Here was his response:
“I do not have any specific advise on diet besides making sure to stay hydrated. It is very easy to become dehydrated at altitude so you need to drink more then you are used to. If possible it is best to get to altitude early. The earlier the better but I have found I like about a week. If that is not possible arriving at altitude right before the race is best. There is a window of a couple of days after getting to altitude that the body usually feels tired because it has been working to adapt to the altitude. This can be avoided by getting there early and adjusting or racing right when you get there. The most important thing to understand while racing, is you simply can not go as fast as at altitude because there is less O2. You need to start conservative and build into it. It is very easy to go under and hit the wall early if you start too fast.” – Karl
There are some people who ascribe to changes in diet for altitude racing. But if you are feeling good in the weeks leading up to a race we wouldn’t change a thing other than increasing water consumption.