Exercise and the gastrointestinal tract. Diarrhea in sports: what to do for runners and cyclists

Review

Runner's diarrhea, also called "runner's colitis" and "runner's rash", refers to a condition that affects runners during and after a run. Long-distance runners (those who run 3 miles or more at a given time) are most likely to experience runner's diarrhea during and immediately after your run. In one study of long-distance runners, 62% of those who participated reported having to stop mid-run to have a bowel movement. >

While doctors aren't entirely sure why it happens, there are ways to identify and manage runner's diarrhea.

Symptoms Symptoms of Runner's Diarrhea

Actual diarrhea is only one symptom of runner's diarrhea. Other symptoms that may occur include:

• acid reflux
• nausea
• convulsions
• D How long does this take?

Treatment Treatment and management of runner's diarrhea

There are steps you can take to reduce your chances of getting runner's diarrhea. Much of the treatment relates to your diet, especially what you choose to eat during the hours and days before long periods of time. You may also want to think about what you wear while working, as clothing that is too tight around the midsection can constrict the blood flow in your digestive tract and make your symptoms more uncomfortable.

Over-the-counter treatments

Over-the-counter treatments such as bismuth salicylate (Pepto Bismol) and loperamide (Imodium) may be an option to stop diarrhea after your run, but be careful. Taking these medications on an empty stomach may simply make you feel sick.

Treatment of underlying conditions

You can also try to determine if you are lactose intolerant, or if you have an underlying condition such as irritable bowel syndrome (IBS). One study found that people with these conditions were much more likely to experience runner's diarrhea. For those people, their diet was the biggest part of solving their symptoms.

What to Eat Foods to Eat and Avoid with Runner's Diarrhea

The easiest way to treat runner's diarrhea is to address your regular eating habits. Certain foods can cause diarrhea and gas, and nausea during a run is likely to occur. Start by thinking about what you tend to eat just before a run, and work backwards as you eliminate foods.

Two hours before your run begins, try to avoid eating anything other than a quick, energy-boosting snack such as whole wheat toast or a banana. Avoid caffeine of any kind in the period immediately before you run, as it acts as a diuretic. If you're prone to runner's diarrhea, try cutting out artificial sweeteners, sugars, and alcohol the night before your run.

Beware of energy gel packs and supplements that are supposed to provide easy, portable "fuel" during your run. Many contain artificial sweeteners and preservatives, which can cause diarrhea. Above all, always stay hydrated before, during and after your run. Staying hydrated can make a difference to your athletic performance.

Emergency symptomsWhen to see a doctor

As with any form of diarrhea, you should stay hydrated if you have runner's diarrhea.

Emergency symptoms include:

palpitations

• severe headache that comes on suddenly
• fainting or loss of consciousness
• bloody or black stools
• diarrhea that lasts 24 hours or more > OutlookOutlook
• By experimenting with what you eat and what time of day you run, you can stop runner's diarrhea while running. Always be careful about dehydration. Sweat you lose over a long period of time, in addition to diarrhea, can increase your risk of losing too much fluid. If you've tried changing your diet and your exercise habits and you continue to experience runner's diarrhea, you may need to talk to a nutritionist or sports medicine specialist.

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Healthcare professional

Overview There are many aches, pains and other sensations that can occur during pregnancy, including stomach tightening. Stomach tightening may begin early in your first trimester as your uterus grows. As your pregnancy progresses, this could be a sign of a possible miscarriage in the early weeks, premature labor if you haven't been induced yet, or upcoming labor.

Sorbitol is an artificial sweetener added to many sugar-free products: chewing gum, candy, cough drops, sports drinks, juices and jams. "When digested, sorbitol pushes water into the gastrointestinal tract, which can lead to diarrhea," says Anish Sheth, gastroenterologist and author of What's Your Poo Telling You. Have you noticed this pattern? Read labels carefully.

Hard training

Whether it's powerlifting, long periods of cardio or cycling, it can all end outside the door with a capital "M". "Really hard workouts pull blood away from the gastrointestinal tract and into the muscles, which causes abdominal cramps and diarrhea, and can sometimes cause bloody stools," Sheth says. It doesn't sound very pleasant - but there is no particular reason for concern. However, if the symptoms are so strong that you periodically have to interrupt your workout to go about your business, it makes sense to consult a doctor - other problems with the gastrointestinal tract may be to blame.

Giardia

Antibiotics

“Many antibiotics recommended during sinusitis or, for example, after any dental procedures, change the bacterial environment of the intestines, causing a bacterial imbalance that negatively affects the digestion of food,” explains Sheth. If you think the reason is the pills you are taking, consult your doctor. By the way, eat more yoghurt - porobiotics will help stabilize the situation.

Hangover

"Carbohydrates, found in large quantities in beer, can add diarrhea to your hangover symptoms - blame their natural fermentation in the gastrointestinal tract," says Sheth. In addition, alcohol has a stimulating effect on the muscles of the gastric tract, causing them to work faster - even too fast. If you have too much in the evening, do not forget to drink water the next morning to avoid long vigils on the toilet.

1. Why is so little currently known about the effects of exercise on the gastrointestinal tract?

Over the past 15 years, the increase in the medical literature has corresponded with an increase in general interest in various types of physical exercise, both casual and recreational exercise and serious competitive sports. Much has been done in the area of ​​research into how athletes can optimally rehydrate during training and competition. These studies focused on changes in the stomach's ability to evacuate fluid and nutrients during strenuous exercise. However, the underlying pathophysiological changes that occur in the gastrointestinal tract during exercise are still largely undefined and unexplored. Physical exercise causes additional stress in the gastrointestinal tract. Knowledge in the field of sports medicine can help to understand the physiology of basic digestive processes, similar to those situations where diseases of the gastrointestinal tract are caused by various toxins or infectious agents.
Until recently, very little attention was paid to the study of the physiology of the gastrointestinal tract during physical exercise, both in healthy people and in patients with various diseases of the gastrointestinal tract. A huge amount of work has been devoted to the study of diseases of the gastrointestinal tract, but almost always various pathophysiological changes have been studied exclusively at rest. Any experimental stress effect on the organs of the gastrointestinal tract, caused either by disease or by medications, is studied using currently existing experimental techniques that are designed for use at rest. These techniques are not easily modified for use during exercise. Gastroenterological physiologists currently do not yet have sufficient knowledge to study the functions of the gastrointestinal tract during exercise. On the other hand, exercise physiologists have shown very little interest in the functions of the gastrointestinal tract, other than studying the optimization of gastric emptying in athletes during competitive sports.

2. What physiological changes are observed in the gastrointestinal tract during exercise?

The basic questions of the physiology of the gastrointestinal tract during physical exercise have not yet been studied. However, it has been established that visceral blood flow is redistributed towards working muscle groups and can decrease to 50-80% of the control level (existing at rest). Such changes in blood flow can also occur with hyperthermia, dehydration, and the use of certain medications (such as NSAIDs). Functions Autonomic (vegetative) nervous system also change with physical exercise. When performing heavy physical exercise and stress, the functions of the sympathetic nervous system predominate. When performing normal exercises (physical exercises or during active recreation), adaptation of the autonomic nervous system occurs and a slight predominance of its parasympathetic department occurs. It is known that during exercise the production of hormones of the gastrointestinal tract, which leads to disturbances in motor activity, absorption capacity and changes in other functions of the gastrointestinal tract. Mechanical effects from running, jumping and other physical exercises that lead to increased intra-abdominal pressure can also change the functions of the gastrointestinal tract.
The major organs involved in nutrient digestion (stomach and colon) are particularly sensitive to ischemia that occurs during strenuous exercise.

3. What symptoms of the gastrointestinal tract are most often observed during exercise?

Many studies have shown a significant predominance of gastrointestinal symptoms in people who exercise. It has long been known that long-distance runners are most often affected. After finishing a run, they often experience heartburn, cramping abdominal pain, an urgent urge to stool, and loss of appetite.
In a study of a large number of marathon runners, it was found that almost 50% of them had loose stools, and 13% had 3 or more stools per day. The most common symptom among runners is defecation urgency. Heartburn occurs in approximately 9.5% of them and worsens while running. Nausea and vomiting are most common during very intense running and long distance running. Women athletes are diagnosed with gastrointestinal symptoms more often than men. Sometimes runners experience bleeding from the rectum while running. These symptoms occur primarily in female and young male runners and tend to occur in athletes who become severely dehydrated, lose more than 4% of their body weight, or drink small amounts of liquids while running. Symptoms such as cramping abdominal pain are also significantly more common in marathon runners than in shorter distance runners. Similar symptoms, predominantly involving the lower gastrointestinal tract, have also been reported in sprinters.
Triathletes (triathlon athletes) typically experience more severe upper gastrointestinal symptoms than regular runners during competition. When observing international triathlete competitions, 25-35% of athletes reported various dyspeptic disorders (loss of appetite, heartburn, nausea and bloating). Triathletes tend to eat and drink more during competition than runners, and this may reduce the above symptoms to some extent.

Gastrointestinal symptoms, especially nausea, vomiting and abdominal pain, may be manifestations of dehydration, electrolyte disturbances or hyperthermia, which are detected with appropriate clinical examination. Some symptoms that are common among athletes, such as acute pain in the side, are usually not related to the gastrointestinal tract. Middle-distance runners also sometimes develop pancreatitis. Symptoms that occur during exercise are usually not severe, unless athletes are unable to stop exercising when symptoms occur (for example, during competition).

4. Are esophageal lesions often the cause of chest pain during exercise?

Esophageal lesions in people who exercise usually present as chest pain or heartburn, which occurs as a result of gastroesophageal reflux or esophageal motility disorders. In cases where chest pain appears during various physical exercises, it is necessary to examine the athlete for the presence of diseases of the cardiovascular system. There are several known cases of famous athletes dying during competitions, which indicates that participation in sports competitions, which usually was an indicator of a healthy lifestyle, does not prevent the development of coronary heart disease. In addition, some experiments have proven that gastroesophageal reflux worsens the course of coronary heart disease.

5. How often does exercise cause heartburn?

Heartburn occurs in many categories of people, including athletes. Among runners, approximately 10% suffer from heartburn. When monitoring the pH of the esophagus, carried out in an outpatient setting, it was found that gastroesophageal reflux occurs more often during exercise than at rest. The likelihood of developing gastroesophageal reflux depends on the type and intensity of exercise.
Although gastroesophageal reflux is more likely to occur during cycling, a study of 7 men and 5 women who measured esophageal pH in an outpatient setting while lifting weights, running, and cycling found that running was the most common cause of gastroesophageal reflux. During running, there is a simultaneous increase in the number of episodes of gastroesophageal reflux and an increase in the amount of time that acid remains in the esophagus. In most cases, gastroesophageal reflux occurred along with belching and most often after eating. Patients with gastroesophageal reflux have not previously been systematically examined during exercise.

6. What treatment is effective for heartburn during exercise?

Esophageal symptoms are quite common in runners, but they are usually not severe and do not particularly bother athletes. To treat these symptoms, it is often enough to choose an appropriate diet and eat nothing immediately before the performance. Sometimes there is a need for drug therapy using antacids and histamine H2 receptor blockers. Measurements of esophageal pH performed in 14 runners at rest and during 1 hour of near-maximal exercise with and without ranitidine showed that ranitidine reduced the time of acid exposure of the esophageal mucosa. Taking antacids, and in particular Gaviscon (an antacid containing aluminum and magnesium), also reduces the time the esophageal mucosa is exposed to acid in runners.

7. Does physical exercise affect the motor activity of the esophagus?

During exercise, esophageal motility disorders may occur, which sometimes lead to chest pain that is not associated with heart disease. However, correct assessment of the condition of athletes in such situations, according to the literature, is quite difficult. Most intraesophageal pressure measuring devices are designed to be used at rest and are unable to filter out various movements associated with breathing or simply artifacts from exercise.
With standard measurements of esophageal motility at rest before, immediately and 1 hour after submaximal exercise on a treadmill, doctors did not find any changes in either the amplitude or duration of peristaltic movements of the esophagus. However, after exercise, the pressure of the lower esophageal sphincter increases slightly (from 24 to 32 mm Hg) and then, as the body recovers, decreases again (to 27 mm Hg). More recently, Soffer et al., using manometry in trained and untrained cyclists, found a decrease in the duration of amplitude and frequency of esophageal contractions as exercise intensity increased to 90% VO 2 max. The clinical significance of these changes in the motor activity of the esophagus has not yet been fully determined, just as the mechanism of their development is not clear. There is now some evidence to suggest that hyperventilation and the stress response may also lead to changes in esophageal motility.

8. How does exercise affect the stomach?

Nausea and vomiting are common during or after athletic competition, and disturbances in gastric emptying during exercise can significantly reduce exercise effectiveness and performance, especially during heavy and prolonged exercise. Therefore, the stomach has become the main object (from the organs of the digestive system) of research by physiologists and gastroenterologists who study the effect of physical exercise on the human body. William Beaumont, observing a gastric fistula caused by an abdominal wound in soldier Alexis Martin, found that exercise led to changes in the appearance of the lining and function of the stomach. Disturbances in gastric physiology may manifest as delayed gastric emptying, nausea, vomiting, bloating, or impaired gastric secretion with damage to the mucous membrane and ulceration. Drugs such as non-steroidal anti-inflammatory drugs, usually used to relieve muscle pain, can also affect stomach function and cause damage to the lining of the stomach.

9. How does exercise affect gastric emptying? Does any food or exercise actually matter?

The main factors regulating the evacuation of gastric contents are foods. The rate of evacuation of liquid food from the stomach differs from the rate of evacuation of solid food. Increasing the calorie and fat content of food slows down its evacuation from the stomach. Food temperature, volume, and osmotic pressure also affect the rate of gastric emptying. In addition, gastric emptying may be influenced by the athlete's hydration status and body temperature. Performing various physical exercises in the heat slows down the rate of gastric emptying. Other factors such as gender, stage of the menstrual cycle, smoking and time of day also affect the rate of gastric emptying. For these reasons, it is difficult to compare study results across different exercise routines and different food intakes.
Since athletes generally tolerate the consumption of various drinks well during long competitions, the processes of evacuation of liquids from the stomach were studied in more detail. Some studies have found that mild to moderate exercise speeds up gastric emptying. One study compared the rate of water evacuation from the stomach during walking and running and found that with light and moderate loads, the rate of gastric evacuation increases, which cannot be said about running at an intensity of 74% VO 2 max. The authors, having analyzed these data, suggested that an increase in intra-abdominal pressure leads to acceleration of gastric emptying. Most other work has shown that moderate exercise does not have a significant effect on the rate of gastric emptying of water, glucose, or electrolyte solutions. It has been noted that runners are more likely to experience various gastric symptoms than cyclists and most other athletes, however, when directly comparing the research results, it turned out that, unlike rest, almost all types of physical exercise lead to a slower rate of gastric emptying, and it is the same in runners and cyclists.
Since the rate of gastric emptying of solid food depends primarily on gastric motility, it could be assumed that physical exercise affects the rate of gastric emptying of solid food to varying degrees. Early studies using scintigraphy to compare the rate of gastric emptying of mixed solid food at rest and during moderate exercise on a bicycle ergometer found that these exercises resulted in a modest increase in gastric emptying. These results were subsequently confirmed several times. Another study using scintigraphy to examine gastric emptying of a mixed solid meal in trained runners at rest and after a 90-minute run found that runners had a significant acceleration in basal gastric emptying compared to controls, but exercise had no effect on this indicator.

10. Does exercise have any effect on impaired gastric emptying in patients with gastric paresis and diabetes mellitus?

Several studies have found that light to moderate exercise speeds up the emptying of liquids and solids from the stomach. Interestingly, exercise can also speed up gastric emptying in patients with gastroparesis. We observed one patient with idiopathic gastric paresis, unresponsive to standard treatment with prokinetic drugs, in whom, according to scintigraphy, gastric emptying normalized after he began walking at a moderate pace. No special research has been carried out in this direction.

11. Does exercise affect acidic gastric secretion?

Gastric secretions may be altered by exercise. However, the clinical significance of this fact has not been fully elucidated and it still does not receive due attention. Feldman and Nixon, when examining 5 healthy people from the control group, did not find significant changes in acidic gastric secretion when they exercised on a bicycle ergometer for 45 minutes at an intensity of 50 to 70% VO 2 max. Information about the role of physical exercise in the formation of duodenal ulcers is currently quite contradictory.

12. Which treatment is effective in relieving exercise-related gastric symptoms in patients?

Treatment of patients with gastric emptying disorders is primarily preventive. Athletes should avoid drinking large amounts of fluids and food, but to such an extent that they do not develop dehydration and hyperthermia, which contribute to gastric retention. Drug therapy is of limited value in such cases. Some athletes under stress may develop adaptations to ingesting large amounts of food and fluid during intense physical activity.

13. Does exercise affect the transit time of intestinal contents?

Impaired small intestinal function during exercise can cause runners to experience diarrhea, bloating, and abdominal pain. In addition, routine daily exercise in active patients may alter intestinal transit time and absorption of medications taken. per os. Physiological changes caused by exercise include both speeding up and slowing down the time it takes for chyme to pass through the intestine. The results of using individual techniques reflected in several works are quite heterogeneous. In general, all the identified changes are very insignificant, and doctors believe that such disturbances in the transit time of chyme through the intestine are not of great importance and, as a rule, do not lead to any pronounced clinical manifestations (see table).

14. Does the absorption capacity of the intestine change during exercise?

Exercising can impair the absorption of water, electrolytes and nutrients in the small intestine. This occurs as a result of the interaction of several factors, for example, due to impaired motor activity of the intestine, a decrease in blood flow in it, or neurohormonal disorders. Methods for studying the functions of the small intestine are quite labor-intensive and cumbersome, and therefore the absorption capacity of the small intestine has rarely been studied. Several studies that have used perfusion techniques with triple-lumen tubes to study small intestinal absorptive capacity during exercise have found no changes in the absorption of water, electrolytes, glucose, xylose, and urea, nor a significant decrease in water and electrolyte absorption when excluding exercise. glucose solutions introduced into the intestine. Recent studies of volunteers who performed exercise at 42, 61, or 80% VO 2 max for 30 to 40 minutes used water (with 2 H 2 O), glucose, and electrolyte solutions. The measured rate of appearance of 2H in plasma was higher at rest than during physical activity of low, moderate and maximum intensity. It seems unlikely that the small changes in intestinal transit time observed in these studies could alter the absorptive capacity of the small intestine.
Carbohydrate absorption was studied in six men who walked at a speed of 4.8 km/h for 4.5 hours. While the absorption of xylose did not change, the absorption of 3-o-methylglucose decreased, and changes were detected in the active and not passive suction.
During exercise, the permeability of the intestinal wall may also change. In special studies, the permeability of the intestinal wall to polyethylene glycol-400 (PEG) was changed in 17 men at rest and after walking a treadmill distance for 90 minutes. With the normalization of water metabolism during physical activity, an increase in the excretion of PEG-400 in the urine was noted, which indicates a relative increase in the permeability of the intestinal wall. The clinical significance of this effect is not fully determined, but increased permeability of the intestinal wall may contribute to an increase in the concentration of intestinal immune system antigens, the appearance of some gastrointestinal symptoms, and also lead to the development of anaphylactic reactions during exercise.

15. Can exercise cause permanent damage to the intestine?

The development of transmural ischemia and necrosis of 1 m of the ileum due to non-occlusive disturbance of the mesenteric circulation is reported in a 65-year-old doctor who was admitted to the clinic with abdominal pain after a 6-kilometer training run. This was a reasonably trained athlete who had previously had episodes of profuse watery diarrhea but no other symptoms or risk factors. The necrotic section of the intestine was removed during surgery; the patient recovered, but no longer ran.

16. How does exercise affect the colon?

The most common gastrointestinal symptoms among runners are urgency to defecate while running, abdominal cramps, and diarrhea. According to recently published running club data, so-called "nervous" diarrhea before a race occurs in 43% of athletes, and approximately 62% have to stop while running because they have a bowel urgency. In addition, 47% of athletes experience diarrhea during competition, often accompanied by severe cramping abdominal pain, nausea and vomiting. 16% of athletes develop rectal bleeding and 12% develop fecal incontinence.

17. Does exercise affect the transit time of stool through the colon? Do they cause constipation?

The effect of exercise on colon transit time has been studied in several different ways. As a result of these studies, it was found that the transit time of stool through the colon during exercise usually decreases somewhat. In special controlled studies, athletes underwent various laboratory tests that allowed them to evaluate metabolic changes in the body during a 9-week training period. At the same time, their diet was strictly controlled. When using radioisotope markers, measuring stool weight, examining stool for solids content, measuring stool pH and stool ammonia or nitrogen content, no changes in the transit time of stool through the colon were detected. However, the training regimes were moderate, the athletes did not experience any clinical symptoms, and the differences in the time of passage of feces through the colon were quite high, both in the same and in different people.
In another study, colonic transit time was studied in 6 men and 4 women who were either exercising (intensity of approximately 50% VO 2 max) on a treadmill or bicycle ergometer, or resting. in a chair daily for 1 hour for 1 week. Colonic transit time of stool was measured using a single dose of radiopaque marker. At the same time, the frequency of stool and its weight were recorded. The diet and the amount of fiber introduced into the body were monitored around the clock; in all other respects, the lifestyle of the subjects was normal. It was found that the transit time of feces through the colon decreased from 51.2 hours at rest to 36.6 hours when training on a bicycle ergometer and to 34 hours when training on a treadmill. However, stool weight and frequency did not change, and none of the subjects running on a treadmill developed diarrhea while running.
Newer scintigraphic techniques for measuring transit time throughout the gastrointestinal tract are best used for research purposes when studying the effects of exercise on gastrointestinal function in people who experience any clinical symptoms.

18. Are there effective treatments for diarrhea that occurs in runners?

Colon symptoms that occur in athletes can be treated in a variety of ways. The so-called “nervous” diarrhea before the start usually stops on its own and quickly disappears when switching to a slag-free diet. Sometimes some anti-diarrheal drugs can be used for preventive purposes. Ultramarathon athletes argue that you can "train your gut" by starting with a short duration and intensity of exercise and gradually increasing it. Taking laxatives before sports should be avoided. Severe diarrhea during competition may improve with reduced physical activity.

19. How does the concentration of liver enzymes change during exercise?

In physically active people, the development of liver dysfunction is often expected in the form of changes in the concentrations of certain enzymes, including bilirubin, AST, ALT and alkaline phosphatase. These changes are not common in long-distance runners and are similar to those that occur with myocardial infarction or chronic hepatitis. Such fermentemia usually develops due to damage to muscle tissue. Damage to the liver tissue can occur as a manifestation of shock, overheating and acute necrosis of skeletal muscles (rhabdomyolysis), which can occur secondary to prolonged and intense physical activity, but it develops quite rarely.

20. Is there a connection between physical activity and the development of gastrointestinal cancer?

Over the past decade, several epidemiological studies have suggested that decreased physical activity or a sedentary lifestyle are associated with an increased risk of colon cancer. Most of these studies have examined work-related physical stress, with some authors suggesting that exercise associated with oxygen deprivation is associated with a reduction in the incidence of malignant tumors of other organs. Small prospective studies and animal data also support this assumption.
While the mechanisms of all these changes could only be speculated theoretically, some interesting data were obtained in support of this hypothesis. Exercise may cause a decrease in the transit time of stool through the colon, and this fact has been shown in several studies to be associated with a decrease in the incidence of colon cancer. People who exercise regularly are more likely to consume a high-calorie, high-fiber diet than sedentary people. This diet reduces the time it takes for stool to pass through the colon. In addition, the findings suggest that bile acids, which generally remain unchanged, are present in lower concentrations in the stool of people who exercise regularly. The development of colon cancer is also associated with obesity and increased cholesterol levels, which usually decrease in people who exercise regularly. Some studies have shown that chronic use of non-steroidal anti-inflammatory drugs by athletes and people who exercise regularly is also associated with a reduced risk of colon cancer.

This topic is popular on running forums. Perhaps because it is not often raised “in real life” among a large audience - after all, the problem is “inconvenient”, many are embarrassed by it. Although, according to unofficial statistics, many athletes suffer from diarrhea while running. What should you do so that you don’t have to choose the latter between the finish line and the toilet stall?

How to prevent diarrhea while running?

Experienced runners say that only experience will help in this matter. But to minimize the risk of “ruining your reputation,” you need proper nutrition. There is also a nuance in this issue - each body reacts differently to the same products. For example, one marathon runner claims that oatmeal in the morning before a race is fraught with “disaster”; it is unlikely that you will be able to reach the finish line after it. Another person’s intestines react with a “catastrophe” to , so you have to rely on bananas, and if they are not available at food stations, then this is also a real disaster, because there is nothing else to replenish energy reserves with. Thus, you understand - you need to know how your body reacts to certain foods while running. You can also test them during a regular long training session, although at competitions there is also a psychological, stress factor at work, so it is impossible to predict all scenarios. Runner's diarrhea in many cases turns out to be a "nervous problem."

• The day before the competition, exclude foods rich in fiber, as well as nuts, beans, and raisins.
• There are medications that runners take the night before a marathon to clear out fiber from their intestines. But whether it is worth taking them is better to discuss with your doctor.

Doctors' opinion

Runner's diarrhea is thought to be caused by ischemia, or insufficient blood supply to the intestines as the body redistributes blood from the GI tract to working muscles. Typically, the intestines tolerate this redistribution of blood flow. But for many athletes, the intestinal lining becomes irritated and runner's diarrhea begins. The degree of diarrhea depends on the degree of exertion, the neurogenic response of the intestines in the individual patient, the degree of conditioning and the degree of dehydration.

So you've decided to get back into shape. Congratulations! Your heart, your lungs and your suffering other half received this news with gratitude.

There's no doubt you've read or heard that you should visit a doctor before starting any exercise program. This is great advice, especially if your heart has spent the last decade or so pumping the equivalent of maple syrup through your vessels. Of course, we would never question the competence of people in scrubs, but if you saw one of them, you might want to contact us for sound medical advice*. Because there are tons of horror stories in sports that people don’t tell you about. For example…

Never turn to us for sound medical advice. #5. When you run, you risk pissing your pants.

Congratulations – you have decided to take up running! This will bring the loins of your body into proper shape. So, you put your sports shoes and shorts by the bed, set the alarm for a time that you have never seen on your watch before (now at 5 am?) and prepare to step on the path of personal victories, starting a whole life in which you finally... then you will wipe the noses of these assholes from your seventh grade physical education lessons with your athletic prowess.

And to your surprise, you actually do it. You start on dark, deserted streets. Everything is going just fine until your body notices that you are as far away from the nearest toilet as possible, and you suddenly realize that the drinking session at the Mexican restaurant last night to celebrate the start of your new life may have been not the most optimal solution. Be familiar with runner's diarrhea.

Running is one of the “shaking” sports. The many shocks and vibrations from your feet constantly hitting the ground resonate with your gastrointestinal system, causing it to, ahem, wake up. For the runner, it is its own brown note. And when it sounds, you will run in search of any more or less secluded place, even in a race with the devil himself - if not out of shame, then at least so as not to get caught by the police - just so as not to go home in your pants, which are not at all happy.

Just ask Paula Radcliffe.

Image caption: And here is Paula Radcliffe, who overtakes some guy at a distance of 10 km, while she is seven months pregnant.

Field Radcliffe holds the world record in the women's marathon with a time of 2 hours 15 minutes 25 seconds. Towards the end of the 2005 international marathon, an opportunity happened to Paula: “I was losing time due to stomach cramps and thought that I should go to one place and everything would work out. I certainly didn't want to resort to this in front of hundreds of thousands of spectators. I just needed to go somewhere. I felt it between miles fifteen and sixteen and seemed to endure it for too long before stopping. I must have eaten too much the night before."

She ducked under the railing and did what she had to do. The media, regarding this picture as a moment of shame and defeat in the face of a hidden disaster, broadcast it live to the whole world.

And she won this race. With a result of 2:17:42.

This was not an out of the ordinary incident. According to Danish studies, forty-five percent of all runners experience various types of gastrointestinal discomfort while running. For the most part, this form of incontinence manifests itself in sudden and urgent need and does not necessarily give you explosive acceleration on the treadmill. With forethought and planning, you can reduce these urges and be like the Boy Scouts, always prepared for unexpected attacks. Avoid high-fiber foods at night, stay hydrated, plan your routes to be near public restrooms, and wear thick, fuzzy socks. But the probability is that sooner or later, this cup will not pass you by.

Of course, you can turn your attention to other types of physical activity, like cycling. You know, like Greg LeMond, who won the 1986 Tour de France by shitting himself in his shorts. Hmm... we would suggest trying swimming, but a disgusting picture emerges before our eyes in detail.

#4. Constant sweat without end and edge

You did a great job. Definitely great. You increased the time and frequency of your exercise from twenty minutes a couple of times a week to an hour or more every day. You ran five, ten kilometers. Maybe they swam half a mile and were one of the ten percent who swam first. Bah, you bike ten miles to work and back. And your clothes suddenly became too loose for you, leaving you with no other options but to buy a new wardrobe. A sexy, tight outfit so that all the exciting irregularities of your body appear.

Life has become more fun.

Except, as you've noticed, when you go out with your (touchingly plump, awkward) friends, you always have a sweaty sheen on you, while they're as dry as baby powder. No, not even that. You are sweating intensely. Abundantly. In fact, you always look like you just ran out of the gym or, say, the swimming pool. A swimming pool filled with sunflower oil.

According to Chris Carmichael, trainer for cyclist Lance Armstrong, as you get into better physical shape, you'll break up a sweat faster and sweat more. In essence, by increasing the intensity and duration of your exercise, you are preparing your body to become more and more physically demanding. This manifests itself in different ways: low body fat, increased specific muscle mass, strengthened bone tissue, increased glycogen stores, and decreased heart rate. And you come from the same perspective as basketball player Patrick Ewing.

Your body knows you're about to go on fifty-mile bike rides, and it has to be on alert to cool you down. But it can't tell the difference between a pre-warm-up and a flight of stairs to your office. Therefore, to protect itself, it simply opens the “sweat” taps and lets itself go whenever your heart rate increases an extra beat per minute.

#3. Woe to your legs, nipples and crotch area

One of the most rewarding parts of achieving and maintaining a good body shape is that you become sexually attractive. And not with some artificial tricks of plastic surgery, but for real, just like this sweet girl is able to split billiard balls by tensing her gluteal muscles.

In other words, you will be as attractive as those parts of your body that you will now be forced to hide will not spoil the overall picture.

How are your legs? Your feet won't look their best. People who run three miles a week three times a week or bike a dizzying four miles to and from work don't have this problem. But once you make progress in your training and start pushing yourself to go faster, higher, stronger, you may forget about all your stashes of delicious nail polish and immediately burn your flip-flops. You're not going to wear them anymore because your feet are about to turn into calloused, calloused, nailless hooves.

But these are feet. With the exception of a small group of people with a very peculiar object of worship, the majority of the people do not consider the feet such an attractive part of the body. When sooner or later the time comes to shed your clothes, you think not about your feet, but about things that cause more lust. For example, about nipples. And in an even narrower sense, you will think about not allowing anyone to even touch your nipples from now on.

The skin on your nipples, unlike the skin covering the rest of your body, does not have the potential to develop calluses. Sweat leaves behind a layer of salt, rough as sandpaper. That plus rubbing your nipples with a T-shirt equals bleeding nipples.

#1. Your farm is disappearing

As for you, men, let's say you decide to become even more masculine by lifting heavy, masculine objects and putting them down again. Pump weights over and over again until your muscles are engorged, your biceps bulge, and you look like a young Schwarzenegger. And so, after you’ve sweated seven times like a man and studied your dazzling, chiseled forms in the mirror, quite possibly flexing your pectoral muscles to the rhythm of the 1812 Overture, you enter the men’s shower to wash off the strong masculine smell. And already in your soul you make the discovery that you now have no testicles. You have essentially turned into a Ken doll.

Whether you're a runner, a cyclist, a swimmer, or a reckless parkour competitor testing the patience of gravity, you'll soon discover that long cycles of continuous physical exertion cause your genitals to tighten. And by compression, we, without exaggeration, mean drawing them inside your body. Luckily, they return to normal within an hour or so. Although it may seem longer.

For the ladies, all you have to worry about is the “jock triad,” a condition that includes negative body image, eating disorders, and menstrual irregularities. It usually affects women who participate in sports that require low body weight to win, such as running, swimming and cycling, which reduces energy expenditure and allows for better performance.

Low weight with a low-calorie diet leads to brittle bones and amenorrhea - the absence of menstruation for three or more months. Depending on the sport you play, you can expect this to happen between 3.6 and 66 percent, compared with a 2 to 5 percent chance overall.

With all this, we would venture to suggest that if a woman is a delicate creature made of skin and bones, also fragile, unable to get pregnant at the moment, then in the eyes of any male this automatically turns her into a dream girl. So you, uh, have something to expect from them.