Nope, shouldn't be a problem. When you take in high GI carbs during/after a workout, you're mainly looking at insulin independent glucose uptake. To put it non-scientifically but somewhat accurately, insulin works by pushing nutrients into the muscle cells. But after a workout, when your muscles are somewhat glycogen-depleted, they're just sucking up the glucose. So there's not as much of an insulin spike as you might think there should be from all that sugar. Also, even if there were, spiking insulin a few times a week doesn't cause any harm in an otherwise healthy person.