Fruit is composed of mostly short glucose polymers that can be easily digested, with in a matter of 30 min actually. I think what @alexanarcho means is probably eliminating more complex sugars like starches, and added fructose, these sugars take an entirely differ metabolic pathway in the body - namely they are broken down in the liver.

Fruit is the best source of all natural simple sugar, and your going to need lots of it when you workout. I'm fan of cardiovascular health over weight lifting too, but if you want a nice tone body I'd incorporate sprints, and squats. Basically work from the ground up. Good luck.