"No pain, no gain." It's a saying so fully ingrained in all of us that regardless of the situation—be it work life, personal life, or gym life—we assume it holds true.
Yet that's not always the case.
If by pain you mean hard work, then, yes, it's true; you need to work hard in order to get results. But when you're talking about physical pain—especially as it relates to training—you have to take a step back and re-evaluate the situation. While pushing through the pain might seem possible at the moment, it can exacerbate your injury. On the other hand, nursing your injury and avoiding all activity can prolong your recovery.
Armed with a little knowledge and the help of a physical therapist, you can continue to rock your goals without compromising your rehab and future results.

Why You Shouldn't Push Through The Pain

"I'm injured, but I can push through it."
As a physical therapist, I hear this all the time. Trust me, I totally get it. There is nothing more frustrating than an injury preventing you from training the way you want. Even if we know in the back of our minds that we should be careful, we're often our own worse enemy and disregard our intuition. We know better, but we're quick to think, "Is it a really a big deal to train through the pain? I mean, you hear about athletes doing it all the time, so it can't be that bad, right?"
The truth is, when it comes to training, you don't want to push through physical pain. Sure, professional athletes competing in a crucial game might weigh the cost versus benefits and choose to suit up rather than sit on the bench, but that's an exception.
I won't get too science-y here, but if you ignore pain, the number of adjustments your body makes to minimize that pain will ultimately lead you to overcompensate in other ways and move differently than normal. Small compensations might initially help protect you from pain and injury.
But when adopted on a long-term basis, they can cause movement dysfunctions, muscle imbalances, and future injuries. Even once the pain is gone, issues from overcompensating often stick around. You're left with a permanent reminder of your desire to push through the pain even when the initial injury has healed.
These small compensations are often simple changes like a slightly different gait or relying more on your joints than your muscles for stability. Think of a simple ankle sprain. While limping initially seems like a good idea, since it lessens your pain, it also causes your hip to move differently, which in turn causes some muscles to do more work while others shut down.
If this only happens temporarily, no big deal. But sometimes, even when the limp is gone, the altered motor programming at the hip can persist and lead to other injuries such as low back or knee pain.

Why Sitting At Home Is No Solution, Either

Now that you're convinced that pushing through the pain isn't worth it, you're likely headed home to rest your injury. Before you prop your feet up and sit back, know that resting an injury can be just as bad as overdoing it. Prolonged rest can result in weakness at the injured site. This can lead to chronic pain and an increased risk of re-injury.
To rehab your injury, you need to load it in a smart and safe way. This is where a physical therapist can help guide you, depending on the placement and severity of your injury. This will likely mean modifying your training program by adding a few specific exercises to rehab your injury, incorporating alternate movements that put less strain on your joints, or taking some exercises out all together.
Let's go back to that ankle-sprain example. I cannot tell you how many people I have seen with chronic ankle, knee, or hip issues that resulted in a poorly rehabbed sprain. A regimen to properly rehab a sprained ankle would likely include retraining the small muscles of your foot and ankle by doing a variety of single-leg exercises, starting with basic balance and progressing to more advanced single-leg squats, Romanian deadlifts, and plyometrics.
The key here is knowing when to push and when not to, something else a physical therapist's guidance can help with.

How To Train With An Injury

When you experience pain while performing an exercise, have an experienced professional examine your form. Are you performing the exercise in a way that exerts unnecessary pressure somewhere, or are you putting yourself in a poor positon or using the wrong muscles? Once you know where you stand, ask yourself (or your PT) what modifications you can make so that exercise is pain-free.
I can't tell you how many times I've helped someone who has trouble lunging transform their workout within 5 minutes. All it took was a few simple tweaks such as shortening their stride or changing the angle of their back. Sometimes, switching a back-loaded exercise to a front-loaded one makes all the difference. There are many modifications that can be done for most exercises to ensure that you're not surpassing the pain threshold.
If your form is on point and you are experiencing pain even with modification, it's not worth forging on with that particular exercise. Instead, you should work with a professional to determine which exercises you can do pain-free to keep you working toward your fitness goals and to help rehab your injury as quickly as possible.
Trust me, I have seen far too many people who regret their stubbornness when a minor injury flared into chronic pain because they refused to rehabilitate it properly. Don't be one of these people!