Tips from Nancy Clark
Transit Troubles and Intestinal Concerns
"More marathons are won or lost in the porta-toilets than
at the dinner table" proclaimed marathon king Bill Rodgers
while talking to a group of runners. You can fully understand the
truth in that statement if you are among the many athletes who worry
about unwanted pit stops, abdominal cramps or diarrhea. Transit
troubles and gastro-intestinal (GI) concerns are surprisingly common
among both athletes and non-athletes alike.
An estimated 30 to 50% of distance runners experience intestinal
problems related to exercise.
The vast majority (83%) of 471 marathoners who completed a survey
reported they suffered GI problems occasionally or frequently during
or after running: 53% experienced the urge to have a bowel movement
and 38% reported diarrhea. Women were more likely than men to experience
Among 155 mountain marathoners, 24% had intestinal symptoms; 2
dropped out due to GI troubles.
Dieters (including athletes--and those with eating disorders) are
more likely than non-dieters to report abdominal pain, bloating,
diarrhea and constipation.
In a random survey of 2,500 Americans, 40% reported one or more
digestive symptoms in the month prior to the interview: abdominal
pain (22%), bloating (16%), diarrhea (27%). These problems were
more prevalent than expected and more prevalent among women than
Given the above data, we need to acknowledge this fact: bowel problems
are a concern for many active people. Yet this topic is rarely discussed;
few athletes feel comfortable discussing their dilemma with diarrhea.
This article addresses this concern and hopefully can reduce your
Causes of "runners' trots"
Many physiological facts help explain why diarrhea is a concern
for athletes, particularly athletes in running-type sports: "jostling"
of the intestines; reduced blood flow to the intestines as the body
diverts blood flow to the working muscles; changes in intestinal
hormones; altered absorption; dehydration. Add high intensity exercise,
stress, anxiety, pre-event jitters, and little wonder athletes--particularly
young and novice athletes whose bodies are yet unaccustomed to the
stress of hard exercise--fret about "nervous diarrhea."
Exercise--specifically more exercise than your body is accustomed
to doing--increases intestinal activity. (Even strength training
accelerates transit time from an average of 44 hours to 20 hours
in healthy, untrained 60 year old men). As your body adjusts to
exercise, you may resume standard bowel movements. But not always,
as witnessed by the number of experienced runners who carry toilet
paper with them during exercise, and also know the whereabouts of
every public toilet on the route.
To help alleviate the problem, try exercising lightly before the
event to help empty the bowels. Experiment with training at different
times of the day. Visualize yourself exercising with no intestinal
problems; the problem may resolve with a positive mindset and experience.
Fuel wisely; the following nutrition tips might help reduce the
1) Reduce your intake of high fiber cereals. You don't need the
roughage! Fiber increases fecal bulk and movement, thereby reducing
transit time. Triathletes with a high fiber intake reported more
GI complaints than those with a lower fiber intake.
2) Limit "sugar-free" foods such as sugar-free gum and
hard candies that contain sorbitol. This type of sugar can cause
3) Keep a food & diarrhea chart to pinpoint food triggers.
Take away any suspicious foods--excessive intakes of juice, coffee,
fresh fruits, raisins, dried fruits, beans, lentils, milk, high
fiber breads and cereals--for a week and then eat a big portion.
Observe changes in bowel movements. If you stop having diarrhea
when you stop eating bran cereal (but have a worrisome situation
when you eat an extra-large portion), the answer becomes obvious:
eat less bran cereal.
To find the food culprit, you may need to look carefully at your
prior diet, because food moves through most people's intestines
in 1-3 days. A simple way to learn your personal transit time is
to eat sesame seeds, corn or beets--foods that can be seen in feces.
4) Drink extra water to maintain hydration. GI complaints are common
in runners who have sweated off more than 4% of their body weight.
(That's 6 lb. for a 150 lb. athlete.) These same runners often believe
the ingestion of fluid causes the diarrhea. The truth is the dehydration
that occurs due to inadequate fluid intake is the true culprit.
5) When all else fails, you might want to consult with your doctor
about occasionally using an anti-diarrhea medicine (such as Imodium).
This may have side effects that hinder performance; be educated.
The bottom line (so to speak): You are not alone with your concerns.
By experimenting with different food and exercise patterns, you
may find a welcome solution.
Nancy Clark, MS, RD is Director of Nutrition Services
at SportsMedicine Associates in Brookline MA. She is author of Nancy
Clark's Sports Nutrition Guidebook, Second Edition ($23) and her
new Food Guide for Marathoners: Tips for Everyday Champions ($20).
Both are available via www.nancyclarkrd.com
or by sending a check to Sports Nutrition Materials, 830 Boylston
St #205, Brookline MA 02467.
Home | Site
Map | Contact Us
About Jeff | Training
| Resources | Nutrition
| Training Groups |
Retreats | Merchandise
Copyright © 2003, JFG, Inc.
Direct comments and questions to email@example.com