Fructose from fresh fruit is a good slow release sugar to consume pre training. It provides good blood glucose control (lower peaks and valleys) so you don't crash during your workout. A lot of big guys and gals I know like to have a protein and honey meal 1-2 hours before their workout.
Fruit is also beneficial when dieting, either as part of a cheat meal/cheat day, or at the beginning of a carb up on a keto type diet. Fructose can preferentially give the liver energy to keep thyroid hormone conversion normal while on a calorie restricted diet.
The worst time to eat fruit (in my opinion) is when you're bulking and well fed (eg for dessert or after a large meal). Fructose is easily and quickly stored as fat if it is eaten when the body doesn't need the calories. But of course not all fruit is high in fructose, and foods such as grape juice are used post workout to assist in shuttling insulin and glucose into muscles because grape juice is relatively high GI.