How do you build up endurance so that you play long pieces with out getting fatigued?

My biggest problem is that, 2-3 minutes into my solo, my hands get tired and I cease to focus on playing musically, and I focus more on getting to the end, no matter how bad it sounds.

Are there books with excersises that could remedy this situation?

Sure you can try doing the "VMax" power strokes...

However, I think that the "Endurance" thing is somewhat of a missunderstanding... I'm sure you practice at least two hours without getting fatuiged, and within those 2 hour stretches you might work on something continuous for 15-20 min., no problem. So the question to ask is why do you lose sight of this ability once you get involved in the full playing of a piece?(which I doubt is much longer than 15-20min) I think it has something to do with losing sight of your physicallity, and focussing more on a goal... getting to the end. Practice is more about moments and the performance becomes getting to the end! You need to practice being aware of yourself and you body while you practice, ie for example( and this may sound wierd to you) are you clenching your sphinxter? are your shoulders at your ear? and very big one... ARE YOU BREATHING.. AND WHEN? there are a billion reasons why one can't play fast or for extreme lenghts very few having to with 8 on a hand for half the day for a year... (just my humble opinion) try to look at what is holding you back and how you are percieving the act of performing the piece? Sorry so long winded . Just somthing alittle out of the ordinary, and by no means am I saying this is the "answer" to your question. Good luck