Likewise, getting ourselves to sustain a change takes "re-tuning" of our emotions. Usually, we change when we're in so much pain that we're willing to expend great effort to move away from it. Once the change starts, however, the pain decreases and with that decrease come a corresponding decrease in the reasons to sustain the change.
The idea is that you are not required to simply endure and live through your emotions. You can change what you feel by how you think. It's work, you get better at it the more that you work with it, just like pushups. By changing how you feel you change your limiting patterns.
What kind of emotional pushups do I recommend? First, make sure you celebrate the goals you complete, both process and outcome goals. After every workout, if all you think of is how hard it was and how much faster you used to be, that's negative emotional pushups. If after every workout, you find something to celebrate in the workout, and you give that celebration some emotional energy, that's emotional pushups. If you have a good food day, and share the satisfaction of that accomplishment with a friend, that's an emotional pushup. If you reach an outcome goal, mark the occasion and share it with someone that you know will understand the significance!
If you can find a consequence of the change that holds an emotional charge - if I lose weight and sustain/regain health and feel better, I'll be a better father/wife or leader - and sustain contact with and draw emotional energy from that, you will be doing emotional pushups.
Emotional pushups help you tap into the emotional drivers that will help you fuel changes in behaviors, thoughts and feelings that betray your well being. Once you tap into this skill, I think you will find it is a deep well of possibility in all kinds of arenas in your life.