Useful habits are formed in 21 days of daily repetitions. In just three weeks, you will train yourself to do what you really need, even if it is difficult or lazy. If you can't get off the ground, remember. You only need 21 days, and then you will do all this automatically.
Do not trust? Do an experiment! Start exercising every day and just don't quit for 21 days. After 3 weeks, it will be very difficult for you to stop doing this.
For 21 days, record your workouts on a piece of paper: “+” if you had a workout and “-” if you didn’t. A sheet of paper is your material appeal to yourself.
Make a decision and go! You will succeed!