Change your location. A different gym or community center might be more conducive to training. Is the area easy to get to? A nice part of town. Even outside is more inspiring to some people instead of indoors.
Change the people around you. Is the current gym a fashion show? A hang out for steroid-pumped cave-men? Maybe, you get bored training solo all of the time. A training partner can boost your morale or hold you back. Carefully select your training partner or people you want to be around. Friendly folk are more fun to train with. Some trainers are a better match than others.
Change the surroundings. You can change your surroundings by placing an exercise mat by your bed or a gym bag by the door. If you belong to a gym, you can try different equipment or a different fitness class. Maybe the cardio room is getting a bit passé for you. Time to try circuit training, rowing or even the power yoga class.
Change the time of your training. Some people like to hit the ground running in the early morning. These morning people like to exercise early to that adrenalin high and a sense of accomplishment. Some people do not get started until noon. Noon training can be a great time to get over that mid-day slump and eat your lunch earlier or later in the day. Then there are the night owls who like being active in the evening. It is a more social time and beats staying home in front of the television set.