I feed my buns frozen banana cubes in the summer, skin on. I toss them in the freezer whole, and then slice them up. I also feed them the peels of the bananas I eat. A little more work because I wash them thoroughly, but it is said to help prevent wool block.
My buns get a fair amount of sugar from their wool block prevention regiment(regimen?), though, and I never see them act hyper. I also give them frozen pineapple in the summer, and a papaya enzyme tablet every day in the winter.