You can significantly lessen or alleviate the fatigue in your hands by using a good pair of cycling gloves (preferably with gel). Handlebar height and seat-forward and back positioning can also make a difference. If the handlebar is too low, you put more weight on your hands, causing fatigue, and if your seat is too far forward it also causes your hands to fatigue.  It is also VERY important to keep your elbows slightly bent while cycling to absorb the shock.