One of the best uses of this log book is as a weekly, or monthly gym planning tool. You can put dates, along with exercises you plan to do on those dates and your plan is ready. And when you will perform these exercises on planned dates, you will fill weights and reps with satisfaction.
Armed with this log book and a well thought plan, you will not be performing random exercises in the gym. Instead, like a sculptor you will be working towards a well chiseled body.