Do You Suffer from Chronic Pain? Exercise Could Help

Health experts have long recommended rest to relieve sore muscles or recover from mild disease, but evidence is mounting that it’s better to keep moving if you have chronic pain. While it may seem counterintuitive to move when it hurts, regular exercise actually increases your tolerance for pain, and the benefit increases the more active you are.

The Pain/Brain Link

Pain is a message to the brain that something, somewhere is wrong. It begins when specialized sensory nerve cells located throughout the body are triggered by a painful stimulus. That painful event, whether caused by trauma or disease, creates an electrical impulse that travels along nerves from the site of the injury to the spinal cord and then up to the brain. While unpleasant, pain serves the important purpose of protecting the body from further damage by triggering whatever action is required to relieve it — moving away from the hot stove or resting, for example.

Following injury or illness, it typically takes about 12 weeks for tissue to heal. Pain lasting beyond that is considered chronic, and it contributes to other physical, mental and social problems, including depression, anxiety, disability and healthcare costs.

What Causes Chronic Pain?

One extraordinary feature of the nervous system is its ability to change, both structurally and functionally, as needed throughout life. This neural plasticity helps us learn, remember and find new pathways for speech and movement following significant brain injuries. While most neural adaptations are advantageous, experts now believe chronic pain is the result of an adaptation, known as central sensitization. This is when the nervous system, after repeated exposure to pain, becomes hypersensitive to it.  This causes pain to persist without cause after the healing period ends.

Central sensitization syndrome is typically expressed as one (or both) of two conditions:

• Allodynia occurs when someone experiences pain because of stimuli that aren't normally painful. It is often associated with these pain disorders:
  • Fibromyalgia
  • Chronic fatigue syndrome
  • Diabetic/peripheral neuropathy
  • Migraines
• Hyperalgesia occurs when a stimulus is more painful than it should be. It can be triggered by traumas and conditions such as:
  • Burns
  • Bites or stings
  • Cancer
  • Opioids
  • Neuropathy
  • Immune/inflammatory conditions
  • Some infections, like shingles and herpes simplex virus 2

People with chronic pain often have more than one painful condition, and they have an increased risk for developing problems with physical functioning, cognition and emotional reactions.

Treating Chronic Pain

For years, healthcare providers recommended rest (and later opioids) to treat both acute and chronic pain, but that view is changing because of the opioid crisis, increasing scientific understanding of pain, and mounting evidence that exercise and activity actually reduce the perception of pain while also improving mental and physical health generally.

A recent study found that the more active participants reported being, the longer they could tolerate mild pain (keeping a hand in ice water). When the study was repeated with the same participants eight years later, those who reported staying active or becoming more active performed better on average compared with those who remained inactive.

The study didn’t identify the mechanism causing this exercise-pain tolerance link, but here are some possible causes:

• Endorphins. Exercise induces hypoalgesia, a reduction in pain sensitivity triggered by the body’s release of endorphins – hormones that bind to the same receptors as opioids and produce a similar pain-reducing effect.
• Endocannabinoids. Exercise increases the body’s production of these neurotransmitters, which affect sleep, appetite, mood – and can improve pain tolerance.
• Pain exposure. Exercise can be somewhat painful: a stitch in the side, an aching muscle, a burning feeling in the chest as you gasp for breath. By exposing ourselves to this type of pain we build resilience and self-efficacy – the belief that we can do certain things despite pain.
• Mood. Exercise improves mood, which makes us more resistant to pain. 

No matter how it works, we now have clear evidence that those with chronic pain should get off the couch and embrace physical activity. Be moderate. Be vigilant. Listen to your body, and move as much as possible.