Taking a break will benefit you and keep you motivated in the following ways:
 Gives your brain time to unwind a little, and get ready to start again. Just like after a long day at work you need a few minutes to unwind, relax, kick off your shoes, etc. before making dinner, taking on the challenges of running a household, or taking care of kids, your mind needs time to get away and unwind in order to stay motivated to meet something especially difficult. If you take breaks, your mental health will be better, and you will be more likely to go back to work gung-ho than if you try to continuously plow through. So, for example, if you are trying to stay motivated to exercise daily, but it is really something you hate, then be sure to take one day off a week. Make Sunday your break day, where you get to unwind, relax, and get your body ready for another week of exercise. If you are a self-employed individual and you are trying to keep yourself motivated to work hard, you will know the benefit of taking a break from your work and letting your mind think of something else. Your mind will thank you. Your brain can be thought of as a muscle, and if you exercise it too much without a break, it can become sore.
 You will be more effective. This of course ties in with the above, but it is true. If you take periodic breaks from what you are doing, and give your body and mind a chance to relax and revamp, when you return to work, chances are you will be far more effective than you were before your break. A break kind of acts like a tune up for a car when it comes to motivation. If you are more effective in what you do, you are much more motivated to do it, and do it well. If however, you struggle through, then maintaining your motivation to do the task at hand begins to dwindle.
 You have a chance to refuel. Taking periodic breaks is great for keeping you motivated because it gives your psyche and body a chance to refuel. You can eat something, rest, change activities, and then gear back up for whatever the activity is that takes motivating. A mother who wants to stay motivated to be the best mom ever needs a break from her kids every now and then just to give herself time to rejuvenate, refresh, and refuel so she can come back full of energy and the resolve to work harder at being a good mom.
 You let go of some tension and stress. When you get a build up of tension and stress you start to get overwhelmed, and then you get behind, and then it is very difficult to stay motivated, plus tension and stress lead to sickness. So, if you take periodic breaks you will be able to let that go. You will be able to protect yourself from illness, and you will be able to stay better motivated to accomplish whatever it is that you are trying to stay motivated to accomplish.