Definitely with the cycle. As with all protein, carbs and nutrients your bodies ability to use these and give the best results is while on a cycle. Honestly though, I really wouldn't suggest getting into that. Maybe if your already diabetic, and still even then I would really reconsider playing around with your insulin levels. If you fu*k up once it could be your last fu*k up. Its serious sh*t and if you don't know EXACTLY and I mean EXACTLY what you are doing one wrong decision can fu*k you up. Not to mention, there are alot of other risks, including becoming a diabetic yourself. But the list goes on and on.
Unless you are competing professionally and are trying to become the best in the world and I wouldn't touch it. Those top pros have doctors, experts, and guys that have done it for years telling them precisely what needs to be done and backing them up.