I've done it for many years, if your going to learn xc, then this is the way to do it.
Training is everything, try and make a 4 mile loop of your normal ride and do it for half hour longer than you intend to race for. (without stopping for breathers)
prep the bike, make sure its bomb proof, nothing worse than paying for a race to not finish it because of something silly.
Hydration, get a bottle on your bike (not a camal pack as these make you too hot while racing) make sure you can reach easily the bottle, as in race conditions getting a space to drink is hard. make sure you are fully hydrated before the race.
apart from that its all about mind set and fitness.
Maybe get a cheap heart rate monitor, i found that was my biggest leap in going forward, knowing how hard you can push and for how long. I was putting too much into the climbs at the start and didnt really recover, where as if your slightly slower and more paced, you can hold that pace for longer.
Lastly, Diet. and this is what ended it for me really, if you want to do well, you have to monitor everything going in.
Drinking a few bottles of red the night before doesnt help
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