Consumption of excess sugar does not lead directly to diabetes, but the excessive caloric intake related to excessive sugar consumption can increase the likelihood of developing diabetes. I should mention that I am a diabetic, so I know a little about this subject.
Diabetes is caused by the body's failure to generate enough insulin or a developed resistance to the insulin it creates. This leads to a high blood sugar level in the body, because the body cannot fully/properly metabolize foods into energy. Sugar is energy....and starches create sugars...that create energy....and so forth...
Large doses of refined sugar will give you a quick kick, but at a high caloric and low nutritive value. A high protein and moderate carb snack/meal after an intensive workout will be much more effective...because the carbs will provide sustained and more nutritive energy, and the protein will provide resources to rebuild muscles, etc.
While there is some recent evidence that small doses of caffeine (i.e. 1-2 cups of joe) might have pain reduction benefits, the fact that it is a diuretic creates a serious rehydration concern. So, the excessive refined sugar and/or coke is probably not your best bet.
What are you trying to accomplish? Are you seeking a energy spike/rejuvenation after your workout? Are you trying to optimize muscles rebuilding after your workout? Are you trying to provide optimal recovery, reduced fatigue/pain after your workout?
Each one of these would require a slightly different post workout meal/snack. Typically, a high protein, moderate carb is best bet....fast digesting carbs don't have to be iv drips of sugar into the blood....so I'd recommend seeking some better sources...so you can get more nutritive bang for the calories...and more performance over long run not a short high...
that's my .02
