I'm a mountain biker, how can i improve my endurance when im going all out and fast?

Question

I'm a mountain biker, how can i improve my endurance when im going all out and fast?

Answer 1

EPO seems to improve a cyclists endurance.

Answer 2

get a heart rate monitor-there cool-you can work in your "zone" for predetermined amounts of time to increase your heart rate and speed

Answer 3

Interval training.  You are going to need strength and cadence to go hard and fast.  Try attacking hills and pushing your way hard up them or going for as long and hard as you can on long flats if you have any and then dropping back down to a normal pace when you get fatigued.

Eventually you're going to be able to have enough power to make it all the way up the hills and you're going to be able to go all out long on the straight flats.