Exercise cannot tighten your loose skin, but you can minimize the amount of loose skin you have. If you have excess skin, patience is key as you wait for your skin to adjust to your new size.
A Pepsi takes between 30 and 45 minutes to freeze solid, depending on the temperature it was at before putting it in a typical home freezer. Be aware that most (but not all) Pepsi containers will burst if you keep them frozen for more than 2 hours.
If you put it in a cooler with just ice, it will take closer to 25 minutes. If you freeze soda, it will expand and likely break out the can-if you are looking for chilled soda, 25 minutes in the freezer or 15 in the ice will bring it from room temperature to chilly.