There are two ways to achieve what you want:

⦁    To motivate yourself (popular way)

⦁    Cultivate your discipline (not the popular way).

In other words, you can wait until you'll be in Olympic shape to start your training, but it's much better to train right now to get your Olympic shape. The point is to cut the bond between feelings and actions and just start to do it. In general, motivation is an attempt to create the desire to act. But discipline encourages you to act, even if you don’t want to.

There's another problem with motivation: it demands constant updating and "refueling". Discipline on the contrary is working like an engine, which steadily supplies energy to the system. From a perspective of consistent long-term results, discipline outperforms motivation.

How to develop discipline?

Build your habits – start with a small goal that is easy to achieve. By achieving the results you'll get the experience of emotional uplift (AKA motivation). Use it to move on to something more difficult that requires discipline.

So the main conclusion: discipline is constant, while motivation is like a flash. In fact, motivation often comes after you start the activity. Screw the motivation, all you need is discipline!