No, you should not drink carbonated beverages when you are exercising. It will cause an upset stomach. Instead you should drink gatorade or water during exercise. It will bring a greater benefit.
You should never drink anything carbonated before during or directly after a workout. This will decrease the amount of oxigen that will get into your blood stream and muscles.
No you should not. Carbonation may have a bloating affect on some due to the bubbles being released in the gastric system. The best bet is to drink water.