How does exercise affect nerve pain?

Exercise helps to alleviate pain related to nerve damage (neuropathic pain) by reducing levels of certain inflammation-promoting factors, suggests an experimental study in the June issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

The results support exercise as a potentially useful nondrug treatment for neuropathic pain, and suggest that it may work by reducing inflammation-promoting substances called cytokines. The lead author was Yu-Wen Chen, PhD, of China Medical University, Taichung, Taiwan.

Exercise Reduces Nerve Pain and Cytokine Expression in Rats

Neuropathic pain is a common and difficult-to-treat type of pain caused by nerve damage, seen in patients with trauma, diabetes, and other conditions. Phantom limb pain after amputation is an example of neuropathic pain.

Dr Chen and colleagues examined the effects of exercise on neuropathic pain induced by sciatic nerve injury in rats. After nerve injury, some animals performed progressive exercise - either swimming or treadmill running - over a few weeks. The researchers assessed the effects of exercise on neuropathic pain severity by monitoring observable pain behaviors.

The results suggested significant reductions in neuropathic pain in rats assigned to swimming or treadmill running. Exercise reduced abnormal responses to temperature and pressure - both characteristic of neuropathic pain.

Benefits of Exercise The benefits of regular physical activity extend to all people regardless of age or condition - whether they are healthy, at risk for disease, or living with a chronic condition or disability. For people with osteoarthritis (OA), regular exercise offers double benefits: It helps reduce the risk of developing other health problems, and it helps manage OA. Research shows that people with OA who engage in regular aerobic and muscle-strengthening exercise can expect:

- Less pain and stiffness
- Increased joint strength and range of movement
- Improved function and ability to do activities
- Potential delay in disease progression

Physical activity also plays an important role in reducing the risk of these common conditions:

- Obesity (a risk factor for OA)
- Heart disease, stroke, and high blood pressure
- Type 2 diabetes
- Certain cancers (colon, breast)
- Depression

How does exercise help?

Scientists are very interested in this question and actively investigating the effects of exercise on OA-afflicted joints. A few things about exercise are known. Exercise strengthens the muscles around joints and keeps them flexible. Strong, flexible muscles do a better job supporting and stabilizing joints than weak muscles. Strong muscles also relieve pain and prevent the pain from activity. Exercise also loosens stiff joints, preserving their ease and range of movement. Finally, exercise that revs up your heart and breathing releases brain chemicals that reduce pain and make you feel good while helping to make or keep you fit.