The next thing to look at, what are the goals of the client? Many clients like personal trainers simply to help them work out, no specific goals but general overall fitness. For these clients, percentages are probably unnecessary as you as the trainer can monitor their intensity and effort by watching. If it is an athlete preparing for their sports, intensities will give you a great guideline to go by and allow you to accurately pick a weight for their work sets that will increase their potential for strength.
What‘s the difference? As with the open-source website editors, it gets a little confusing. Both LibreOffice and NeoOffice run on the Mac and both are open-source. The interface of both look almost identical at first glance, and they both share largely the same features. So why the redundancy and which should you choose? Well, while LibreOffice runs on both Mac and Windows, NeoOffice is Mac only. It is a special branch or fork of OpenOffice that was developed to quash some of the bugs in the Mac version of OpenOffice. So I would say, if you‘re going to choose one, choose NeoOffice.