Active Voice: Exercise Your Pain Away

By Dane B. Cook, PhD, FACSM and Laura D. Ellingson, PhD

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.

Dane B. Cook, Ph.D., FACSM, is an Associate Professor in the Department of Kinesiology and co-director of the Exercise Psychology Laboratory at the University of Wisconsin – Madison. His research focuses on determining the psychobiological mechanisms of pain and fatigue and learning how exercise can be used to better understand and treat these phenomena in healthy adults and those suffering from chronic pain and fatigue.

Laura D. Ellingson, Ph.D., is a Post-Doctoral Research Scientist in the Department of Kinesiology at the University of Wisconsin – Madison. Her research focuses on the influence of exercise and physical activity behaviors on central nervous system processing of pain in patients with chronic pain conditions and healthy individuals.

See the July, 2012 issue of ACSM's Medicine & Science in Sports & Exercise® (MSSE) for the research report they authored with colleagues, entitled “Physical Activity is Related to Pain Sensitivity in Healthy Women.”

Pain is an increasing public health concern. At any given time up to 50% of adults are affected by various acute pain conditions (ranging from everyday aches and pains to serious injuries). Roughly 20% of the population suffers from chronic musculoskeletal pain. The consequences of living with pain are dire. Pain interferes with activities of daily living, negatively impacts personal relationships, decreases work productivity and increases health care utilization. Unfortunately, aside from drugs, there are few evidence-based options for dealing with either acute or chronic pain.

Leading an active lifestyle is associated with numerous physical and mental health benefits. An additional and less well understood benefit of physical activity may be reduced sensitivity to pain. For example, structured exercise is a safe and efficacious treatment for a multitude of chronic pain conditions – leading to improvements in physical function, greater well-being and reduced pain symptoms. Recent data from our lab has also shown that chronic muscle pain patients with higher physical activity levels show brain and behavioral responses indicative of effective pain modulation while those with higher sedentary behaviors show an impaired ability to regulate pain. This research suggests that maintaining even minimal levels of physical activity can help preserve the ability to regulate pain for chronic muscle pain patients.

In our study appearing in the July 2012 issue of MSSE, we extended our work in chronic pain patients to a group of healthy women. Because our chronic pain patients are not very active, we were interested to see if higher-intensity activity associated with meeting physical activity recommendations affects pain sensitivity. To assess this, we recruited women with more active lifestyles than those in our previous studies. We found that women who were meeting current ACSM recommendations were less sensitive to pain than their less active peers. When we examined the data more closely, we found that vigorous-intensity activity was significantly related to pain perception and that moderate intensity activity was not.

Vigorous intensity physical activity is a unique physiological stressor because it is often painful. It also increases peripheral concentrations of noxious biochemicals in the exercising muscles and has significant effects on the brain including the release of pain inhibitory neurotransmitters. It is plausible that repeated exposure to higher intensity exercise that is painful can habituate or condition individuals to pain such that over time they become less sensitive to the pain experienced during everyday life, a positive adaptation.

Exercise and pain research has grown considerably over the past decade. Initial descriptive studies have progressed to more mechanistically driven research questions. Exercise training is now considered to be one of the few consistently efficacious treatments for chronic muscle pain. The long-term goals of our research program are to determine how structured exercise and physical activity influence central nervous system regulation of pain. This will help determine why exercise is an efficacious treatment for chronic pain and whether leading a physically active lifestyle reduces an individual’s sensitivity to everyday pain experiences or even reduces risk for developing chronic musculoskeletal pain.