Well, fructose is not "bad" per se. I have looked at many Gatorade labels, and I have never seen dextrose on it...I have seen "Glucose-fuctose" on it as the main ingredient, but never dextrose...
anyway...
I personally believe that any form of simple carbohydrate, will do for the pre-workout situation...
dextrose, sucrose, fructose, glucose...
all get into the bloodstream fast...
Some guys will kill me for saying fructose is good for anything, but hear me out...
When most of us think "fructose" we immediately think "fruit sugar"...and as we know, all fruits have some form of fiber in them. Fiber slows the release of any carbohydrate from the stomach into the bloodstream to a certain extent.
So, if you were to use fructose in a free form (i.e honey or brown sugar) then you will be pleasantly suprized how well it fares when compared to dextrose or those other carbohydrate isolates.
Case in point:
personal experiences with brown sugar..
I have never in my life experienced a "sugar high", or a burst of energy from eating any form of carbohydrate, until recently. I got the "high" from eating a spoonful of brown sugar, alone, by itself with a cup of water to wash it down...
on an empty stomach, at about 4:00pm I did this last wednesday, and about 20 minutes later I was feeling as if I was jacked on ephedrine or something close to that. It was actually pretty cool
I have used dextrose, glucose and sucrose, and never got anything from it.
But that's just me.