One thing you can do when you start getting bored with your workout is to change the setting or place in which you do it. Always doing your workouts at the gym? Well, invest in a good pair of dumbbells or some other easily portable equipment and hit the park. Doing some of your routines outdoors and in a different environment could not only be a refreshing change, but can also stimulate some creativity on your part. Having access to different equipment (like park benches and monkey bars) can inspire your to perhaps try a few new things for a change. Are you one whe always doing outdoor sports or runs? Well, hit the gym and try taking classes instead. Changing the activity also has the potential to wake up and train a whole new set of muscles you didn't even know you had.
Stuck in the house all the time with your favorite exercise dvds? You know you know all those routines by heart now, you've been doing them for so long. Get out, buddy up with a friend and start doing power walks or park workouts. Being around other people striving to be fit can inspire you and get you off that monotonous home dvd treadmill!
All in all, change is good! It can also be what's needed to keep your energy level high and your enthusiasm for being active alive. Give it a try, folks!