Tuesday, February 13, 2018

Exercise is the Best Medicine - unless you have Diarrhea ... Exercising with Inflammatory Bowel Disease


An estimated 1.6 million people in the United States live with inflammatory bowel disease. Inflammatory bowel disease (IBD) is a term used to describe any condition that causes chronic inflammation along the digestive tract.[1] The two most common forms of IBD are Crohn’s Disease and Ulcerative colitis. Crohn’s disease can affect anywhere along the digestive tract, from the mouth to the anus. Ulcerative colitis is strictly in the colon, which is made up of the large intestine and rectum.[1] They are chronic conditions with unpredictable courses of disease. They can be medically managed, but there are currently no cures. In people with IBD, the immune system reacts inappropriately, and can mistake benign or beneficial cells and bacteria for harmful foreign substances.[1] When this happens, your immune system can do harm to your gastrointestinal tract and produce the symptoms of IBD. Symptoms of IBD can include: Diarrhea, rectal bleeding, urgency to move bowels, constipation, abdominal pain and cramping, fatigue, loss of appetite, and other extraintestinal manifestations. Patients with IBD experience periods in which their disease is active, also called a flare, and periods where they experience no symptoms, also called remission. [1]

Currently, the most common way to manage IBD is with medication prescribed by an MD. Taking maintenance medication can reduce risk of flares. There are various classes of medications depending on the severity of the disease. Paying attention to your diet can be another way to reduce symptoms, replace lost nutrients, and promote healing. Dietary recommendations vary depending on what parts of the intestine are affected and what symptoms you have. Complementary medicine can also supplement conventional medicine. [1]

So where does exercise, especially running, fit into all of this? Can someone with IBD run without affecting their symptoms or the progression of their disease? The possible beneficial effects of physical activity on the gastrointestinal tract have been little studied so far. Unfortunately, the effectiveness of exercise has not been well described in these persons, and the mechanisms of potential benefits are poorly understood. [2] Exercise has been shown to be inversely correlated with systemic low-level inflammation, meaning that regular exercise may be responsible for good health effects in patients with chronic disease.[3] The effect of exercise on different immune parameters could depend on type, intensity, and duration of exercise. Lower and moderate intensity exercises have been shown to be well tolerated in patients with IBD who were in a state of remission. According to a study by Ploeger, et. al in 2012,  moderate intensity exercise did not provoke subjective symptoms or changes in gastrointestinal parameters. This same study found that high intensity interval exercise also did not exacerbate symptoms in pediatric patients. [2] However, a review done by Narula and Fedorark found that acute strenuous exercise may induce transient mild systemic inflammation, increasing the amount of inflammatory cytokines. Intense exercise can impair function of the immune system for several hours. [4] Inflammation is characterized by the interaction of pro- and anti-inflammatory cytokines.[5] Cytokines are small proteins that are important to the function of the immune system. They modulate balance between humoral and cell-based immune response, and regulate maturation, growth, and responsiveness of particular cell populations [6]. Myokines, a type of cytokine, are released during exercise via skeletal muscle contraction. Myokines have an anti-inflammatory effect, which, according to research, makes this a benefit of regular exercise. [6] The proper dosage of exercise may be able to alleviate colitis symptoms, reduce inflammation, and counteract some of the adverse effects of pharmacological therapy. [2]

It seems there is still a need to research higher intensity exercise, as well as longer duration exercise. What is considered high intensity and how is intensity of exercise graded? Exercise activity is graded in metabolic equivalents, or METs. One MET is the amount of energy it takes to sit quietly. [7] Vigorous activity is defined as anything greater than six METs. Activities that are greater than six METs include: hiking, playing soccer, basketball, or running at 6 MPH or faster.[7] In healthy athletes, higher intensity exercise has been found to produce GI symptoms and disturbances. It has been hypothesized that bile, pancreatic secretions, and bacteria cross junctions in the small intestine and can create a local immune response.  This phenomenon was found to occur at 80% aerobic capacity peak exercise, however, it was not found to occur during low intensity exercises, typically between 40-60% of peak aerobic exercise. [8] The urge to defecate is another common GI disturbance during exercise. There is a decrease in colonic phasic activity, offering less resistance to colonic flow and decreased transit time, leading to this urge to defecate. This is an undesired side effect for someone with IBD who is diarrhea-prone. [8] For those with moderate to severe symptoms, exercise may be discouraged due to physical restrictions, inconvenience, and discomfort. [3] There has been limited recent data suggesting that high intensity endurance sports may be safe in some IBD patients. In 2016, a small prospective study of ten IBD patients participating in high intensity exercise had no change in fecal calprotectin (a measure of acute inflammation) levels. These were patients who participated in activities like triathlons, marathons, and long distance bicycle races. [9] Eight of the ten patients had no change in their symptoms or disease activity scores. The two patients with Crohn’s disease who had elevations in their disease activity scores had returns to baseline in these scores within one week. [9]

Exercise in general has positive effects for persons with IBD and other chronic diseases. Persons with IBD are more susceptible to osteoporosis as nutrients are not digested or absorbed as well, and exercise has been shown to increase bone density.[10] Exercise increases flexibility and strength that can reduce joint pain. Fatigue and low energy are common extra-intestinal symptoms. Exercise increases blood flow throughout the body and improves cardiovascular health and fitness. This allows blood and oxygen to be pumped throughout the body, providing energy to do more work. This can reduce the feelings of fatigue. Exercise also can decrease time for gastric emptying and decrease blood flow to the gastrointestinal system. [10] Persons with IBD tend to have higher levels of stress and lower quality of life reports, and stress can aggravate digestion issues. Studies have shown exercise to be beneficial in both of these categories.

Although there are limited studies showing the how long distance or high intensity running positively or negatively affects the symptoms of IBD, the internet and online forums are littered with tales from runners with IBD. It is important to make sure your gastroenterologist is aware of your activity, and be aware of the way your body responds to the activity.  Moderate to severe symptoms may limit the ability to do more intense exercise, but for those in remission or with mild symptoms, there is promising data and anecdotal support. Further research will have to be done to help establish exercise regimens that can account for each IBD patient’s unique presentation.





1.Crohn's and Colitis Foundation. “Crohn's & Colitis.” Crohn's | Colitis | IBD | Crohn's & Colitis Foundation, Crohn's and Colitis Foundation, 2015, www.crohnscolitisfoundation.org/?referrer=http%3A%2F%2Fwww.crohnscolitisfoundation.org%2Fwhat-are-crohns-and-colitis%2Fwhat-is-crohns-disease%2F%3F.

2.H. Ploeger, J. Obeid, T. Nguyen et al., “Exercise and inflammation in pediatric Crohn’s disease,” International Journal of Sports Medicine, vol. 33, no. 8, pp. 671–679, 2012.

3.  Bilski, J., Brzozowski, B., Mazur-Bialy, A., Sliwowski, Z., & Brzozowski, T. (2014). The Role of Physical Exercise in Inflammatory Bowel Disease. BioMed Research International2014, 429031. http://doi.org/10.1155/2014/429031

4.Narula, N., & Fedorak, R. N. (2008). Exercise and inflammatory bowel disease. Canadian Journal of Gastroenterology22(5), 497–504.

5. Cavaillon JM (2001) Pro-versus anti-inflammatory cytokines: Myth or Reality. Cell Mol Biol (Noisy-le-grand). 2001 Jun;47(4):695-702.

6. Cytokines. (n.d.). In Cytokines and Cells Online Pathfinder Encyclopedia version(2013 ed., Vol. 31.4).

7.“Measuring Physical Activity.” The Nutrition Source, Harvard School of Public Health, 29 Sept. 2017, www.hsph.harvard.edu/nutritionsource/mets-activity-table/.

8. Ng, V., Millard, W., Lebrun, C., & Howard, J. (2006). Exercise and Crohn’s disease: Speculations on potential benefits. Canadian Journal of Gastroenterology20(10), 657–660.

9. Hassid B, Lamere B, Kattah M, Mahadevan U. Effect of intense exercise on inflammatory bowel disease activity. Am J Gastroenterol. 2016;111(S1):S260–S336.

10.Perez, C (2009). .Prescription of physical exercise in Crohn's disease Journal of Crohn's and Colitis, December 2009: 3(4):  225–231,