Nearly every runner has experienced it: You take a few weeks off for an injury, only to return to running with the pain still there. You went to therapy, got a chiropractic adjustment, massage, did your exercises, even changed your running form, cut your mileage, and bought new shoes.
So why did the pain stick around even though you gave yourself ample time to heal? The answer may lie in pain science, one of the most complex yet critical areas of sports medicine.
Conventional thinking ties running injuries to particular damage, such as an inflamed tendon or strained muscle. This thinking often leaves runners puzzled after days and weeks of injury. "How can I be in such pain with no signs of swelling, no outward damage and without running at a fast pace for very long?" Unfortunately, the message of pain science is often oversimplified as "pain is all in your head."
Quite simply, pain is based on the body's perception of threat. In many cases, this is a good thing, as pain helps protect you from damage. If you put your hand on a hot stove, you want the body to feel pain. If you tear a muscle or a tendon, pain is a necessary reminder to stop using the injured limb. The problem in running is when the brain decides to continue saying "ouch" after the tissue has healed. After an injury, the body retains discrete memories associated with specific painful experiences. Sometimes when healing occurs, the body may treat these painful memories as reality even when there is discord between the brain and tissue.
The key to transitioning runners from painful running into pain-free running is to input new memories.
MRI images, often considered the gold diagnostic test of trauma or injury, are poorly correlated with pain in two commonly injured body areas for runners—low back and knee. In other words, you can take MRIs of injured and uninjured individuals and tell almost no difference between them. That's not to say that MRIs are useless; they are essential for diagnosing many serious and potentially life-threatening conditions. For runners with pain, however, MRIs should be considered only in the full context of the individual runner's background.
How can we apply pain science in practice? The first step is to get your mind in the right place. There's ample research to show that high stress, both physical and mental, can increase injury risk and prolong recovery.
Just as pain can be a good thing, stress serves a vital role as well. We never want to completely de-stress, just like we don't want the volume on the radio too low or too high. Stress is often expressed by how the body perceives a threat. If the brain perceives the running experience as threatening, you'll often find yourself in pain, unable to get very far on your runs. So what can you do in your training to optimally modulate stress, knowing that you must deftly strike a balance?
Aim for "Easy Victories"
Most runners are familiar with run-walk intervals for beginners and fast intervals for advanced runners. Yet, running slow intervals is one overlooked way to rebuild fitness after an injury. Many runners report pain onset at 10 to 15 minutes into a run, yet continue to run despite the pain and then limp home in frustration.
Instead, if you run short intervals of 1 to 5 minutes, you may be able to accumulate significant amounts of pain-free running. For general fitness, you can insert upper body exercises into the rest breaks to maintain full body conditioning during the period of reduced running. Slow intervals are "easy victories" in the rebuilding process toward pain-free running.