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 International, 2014, 429031. http://doi.org/10.1155/2014/429031
4.Narula,
N., & Fedorak, R. N. (2008). Exercise and inflammatory bowel disease. Canadian
Journal of Gastroenterology, 22(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
Gastroenterology, 20(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..Prescription of physical exercise in Crohn's disease Journal of Crohn's and Colitis, December 2009: 3(4): 225–231,