Serious People write down just about everything they do when it comes to accomplishing a particular goal or target. Studies have proven when you write your goals or feelings down, they tend to mean more and can easily be used as motivation.
Keep a journal of how you feel before and after exercise. Especially the great workouts.
On the days you just don’t feel like exercising, look back on the good workout days for some inspiration.
Keep training hard, write your goals and feelings down and stick with the plan.