<em>True </em>- you do not have to do this specifically, but it is one of the best ways to prepare for a workout. It can help to reduce the chance of pulling / straining something while working out. You also want to "cool down" or do a similar stretching routine after working out to help your body recover.
Athletes should stay away from tobacco use because it has been scientifically proven that smoking, vaping, and chewing tobacco can cause multiple types of cancers and can even decrease your lung compacity making it harder for you to breathe.