They drain your energy, and sap your desire to work out. In my opinion there is nothing worse that dealing with physical pain--especially if you desire to be active.
It starts out as a little pain when you do specific movements and then, like a virus, spreads to the rest of your life. It's absolutely miserable.
Pain is the #1 killer of fitness and strength progress.
Even as an expert with over 10 years of experience, it got me too. It was so bad that at one point I couldn't walk for an entire week due to back and hip pain. Going from an elite level of strength to crippled and unable to walk was psychological torture.
Unfortunately there just isn't a lot of quality information out there to help. A great therapist is hard to find--and expensive. Many people who experience pain end up giving up.
My purpose in life is to help you get back your physical freedom. I want you to have such a solid foundation of pain-free, athletic movement that you can try any activity your heart desires. Whether that is tennis, kickboxing, or walking up the stairs without your knees hurting. The secret to lifelong fitness is to have as many options as possible. The way you do this? A foundation of mobility and strength throughout the whole body.
What many people don't know is that pain can come from a wide variety of sources. Quite often the SOURCE of the pain is completely different than where it actually hurts.
A great example of this comes from Simple Shoulder Solution:
In this book and video series I go over the step-by-step process to understanding shoulder mobility.
First, you must have proper breathing mechanics and core strength--this lays the first foundation for quality movement throughout the rest of the body. If this isn't functioning properly, you will likely have dysfunction that spreads throughout the body through compensation patterns.
Next, you must mobilize the thoracic spine (mid back) and neck. If these cannot move properly it will prevent you from moving your scapula (shoulder blade) properly.
FAR too many people ignore the importance of being able to move their scapula through a full range of motion with strength and control. If you don't have this, it is essentially IMPOSSIBLE to have healthy shoulders. If the scapula doesn't move well it will wreak havoc on the ball and socket joint (glenohumeral joint, for us nerds).
Finally, only after we address the previous areas above, can we even begin to look at the ball and socket on the end. Unfortunately most people with shoulder problems simply try to stretch and crank on this joint--which happens to be the most vulnerable AND mobile joint in the body already.
You can imagine what just stretching it more would do to your shoulder...It would create MORE pain and dysfunction.
The last thing you want to do is become more sedentary. Rest the painful motion, but introduce as much non-painful movement as you possibly can in the rest of your body, and in that area. Don't do anything that creates a sharp pain.
MAKE MOVEMENT A HABIT
I recommend every human move their joints through their full range of motion EVERY DAY. The key to doing that is to make it a habit. I have found that the best time is in the morning when you wake up. This gives you the highest benefit, and makes it a real priority. Check out this post on how 5 Minute Flow can help you nail this movement habit--no equipment or experience required.
BUILD A SOLID FOUNDATION
Make sure the affected area has a proper foundation in the surrounding structures. This can be as simple as getting your core and hips stronger to take the pressure off of your low back or improving your neck and spine flexibility to let your shoulder heal. I mention this principle in greater detail above, and in all of my mobility courses.
MAINTAIN A POSITIVE ATTITUDE
Focus on what you CAN do vs what you can't do. Pain is just as much psychological as it is physical. The biggest difference maker is adapting to your environment. If you have a messed up knee, do everything you can to fix the problem WHILE getting amazing at pushups, pull-ups, handstands, and front levers. If your shoulder is aching work on the Simple Shoulder Solution drills AND get your legs stronger and more powerful than ever before. DO NOT GIVE UP. KEEP MOVING.