We all have exercises that we love to hate, but we do them anyway because they really provide results. I call these my "suck-it-up" exercises... as in, "quit whining, suck it up and just do it".
It is a mind over matter battle though to get the point where I can transition from attempting to talk myself out of doing that exercise to actually pushing through it and/or pumping it out. After all, humans inherently don't like to be uncomfortable. We invented cars, air conditioning, and chocolate chip muffins so that our lives would be more comfortable. But a little discomfort is a good thing... it means we've reached an area in our life where we need to explore, stretch, and grow. And after we get through that discomfort, we are better equipped to handle future challenges or situations that come our way. Conquering discomfort makes us grow mentally, emotionally, spiritually, and physically.
In a fitness setting, if we find ourselves doing an exercise that is not comfortable, it most likely means our muscles and body are currently not capable of bending, pushing, or pulling in a specific manner. (It could also mean you have incorrect form, but that's a different subject.) However, once we learn the appropriate technique and try that exercise once or twice, our muscles and bodies begin to learn the movement and make neurological changes which increase our performance; i.e. make us stronger, more efficient at performing a given task, or enhance our endurance. After a little while, that exercise is no longer quite as uncomfortable and we may notice our body feels different, stronger, or leaner when we perform that exercise.
In the posts below, I discuss some of my favorite "suck-it-up" exercises that I once abhorred, but now try incorporate into my routine on a regular basis. I don't love them simply for what they are, but rather for what they've made me overcome. And I do enjoy the satisfaction of conquering an obstacle and knowing that my muscles have made positive gains because of these exercises.
Favorite Suck-It-Up Move for Core
Favorite Suck-It-Up Move for Upper Body
Favorite Suck-It-Up Move for Lower Body
Important disclaimer: let's not confuse minor discomfort with pain. If at any time you feel pain while exercising, you should immediately stop what you are doing. Depending on the severity of the pain, you may need to seek advice from a medical professional.