Want to get the habit of working out? No matter what just every day get up, put on your gym clothes and go to the gym. Even if you don't end up working out because you don't have the energy, you have the habit of going to the gym, and more than likely once you are there you will find the energy to do at least something. But if not, you take a shower and head to work. Try it. It might work for you.
I'm an athlete and an entrepreneur. Bicycles are my hobby - I am trained to build them and fix them, and I enjoy riding them!