Something that we see a lot in the fitness world is people doing exercises just for the sake of being able to say "I can do ___x___" rather than for the actual benefit of the exercise itself.
Let's take pull ups for example. A pull up done properly is one of the most bang-for-your-buck bodyweight exercises out there. They help to strengthen your grip, build a stronger back and shoulders, and challenge your trunk (core) amongst many other benefits. However, you'll notice that I said a pull up done properly can offer all of these benefits. For reference, to perform a proper pull up, an athlete begins from a dead hang with the arms fully extended overhead. Keeping legs straight, they then proceed to grip the bar tight and pull their entire body up until their neck touches the bar. Then under control, the athlete lowers their body down in the reciprocal manner. This is how you get the benefits of a pull up that I described above.
Setting a goal to be able to do a proper pull up (video above) in order to receive the benefits of doing pull ups is great! The problem we are seeing, is people focusing way too much on the outcome (doing a pull up) and forgetting that it's actually the process (moving better and getting stronger) that matters. When this outcome-based approach takes over, we start to see things such as kipping pull ups (see video below) or compensatory strategies just so that a person can say, "I can do a pull up."
As soon as you add kipping (before you can actually do a strict pullup), kicking, or compensating of any form to a pull up, you lose the benefits of that movement. Kipping for example places all of the stress on the joints rather than relying on muscle tissue to do the work. Our joints aren't meant to handle that type of stress, and will eventually break down in the form of a shoulder or elbow injury. (I gave another example of this on my instagram page which you can follow for more health and fitness tips!)
This concept goes for each and every exercise we teach. We teach them because they contribute to you functioning better as a human. But, if you rush to accomplish the outcome of simply completing the exercise without appropriately progressing, you completely lose the benefit of the movement.
So, the next time you find yourself straining, holding your breath, flailing around, or whatever other way you might compensate during a given exercise, ask yourself if it's worth it. Or would it make more sense to scale back the weight/difficulty a bit and focus on really good, well-executed repetitions?
I'll answer for you - it's the latter, every time!