Warm ups help prepare you for whatever exercise you will be doing. They help prevent injuries by stretching the muscles and increasing blood flow to them, and loosening the joints. So without warming up you are putting yourself at risk of injury and increased muscle soreness later.
Warm ups help with injury prevention and reduce soreness that may result from muscles that haven’t been prepared for movement (they need to be stretched, blood circulation and body temperature need to be increased).
because it keeps your heart healthy and other brands of cereal dont/ they are made up of mostly sugar and will most likely do the opposite from raisin bran.