much weight, you will be able to look back and see exactly what the difference was. this will let you either drop back down to the original weight or go between the two weights.
another reason keeping a journal is very important when it comes to your workout routine is in case of any injuries. if you hurt a certain muscle in the gym, it can be hard to realize exactly what exercise did it. if you are trying new machines and routines everyday it will be hard to remember which one hurt that certain muscle. with a workout journal, you can flip back through the book to see what exercise 