Stomach problems in triathlon, written by Bart Cooymans and Tim van de hemel

A feeling that your food is not absorbed, the feeling that you could cramp up at any moment, abdominal pain, thirst. All factors related to your nutrition that make it a lot harder or even impossible for you as an athlete to reach the finish line during an Ironman.

Where do these problems come from, what can you train for, and what should you consider on race day?

The cause of stomach problems cannot be attributed to one cause, the body is a complex set of systems that are all connected to each other. Even when a heavy effort is made it all has to run in the right direction, but some people suffer more and faster than others.

In this blog we will discuss a number of different causes and strategies to deal with this, so you can increase your chances of a successful performance on race day!

Possible Causes

Stress

In sport, psychological stress also translates into physiological stress and thus has an impact on the digestive process. Think for example of the number of toilet visits that have to be made on the day of the race or just before the start.
Often this stress does subside in part once the race is underway, although certain specific situations during the race can still be a trigger. Some are more susceptible than others. Being aware of it and taking it into account is already an important factor.

Intensity

At low intensity, relatively less blood goes to the muscles alone. At higher intensities, the body is under much more physiological stress and literally less energy (blood) goes to the gastrointestinal system. This can lead to complaints if it is not handled adequately, which is why a race-specific training combined with testing your nutrition plan is recommended in advance.

Mechanical load

Walking, especially the vertical displacement, is a taxing movement for your gastric system. This can cause discomfort and/or decreased absorption through your digestive system.
Athletes who are sensitive to this need to figure out how to get their required carbohydrate intake over time. One option in triathlon is to optimize this on the bike, but this can also be done by taking other foods that are less liquid during the run. Hydration must of course be taken into account.

Hydration

Status of dehydration

You drink to get nutrition (ovv sugars), but also (and especially) to stay hydrated. If you don't get enough fluids as you use them through combustion and transpiration, you get a negative fluid balance. This with all its consequences: muscle cramps, dizziness, stomach problems, . to even loss of consciousness. This is not the place you want to be as an athlete who still expects performance from his body. It's a matter of staying ahead of this by taking in enough fluids, taking into account external factors such as heat, level of exertion, etc.

Everyone knows the feeling: just taken a good sip of your sports drink and at the next uphill section you feel your stomach rumble. Triathletes know this feeling when they jump off the bike and start running. Anything but pleasant. This can be avoided by dividing your drinks and not drinking too much at once. So, dosage and timing!

A phenomenon that is sometimes cited as a guideline is: drink to thirst. The disadvantage of this principle is that you have actually lost too much fluid, then get a signal (thirst) and only then start supplying your body. The problem with this is that it means you are always too late. Think of a long endurance ride, there you also start eating from the beginning of your training to provide your body with energy in time, not only when you start to feel faint because of the glycogen and blood sugar shortage that has occurred because you took in too few carbohydrates too late.

Salt water

Triathletes whose first test is an ocean swim are advised not to drink too much seawater during this test. The high salt content in the water can cause faster dehydration or just give you a thirsty feeling so you will drink too much in a short time. Do you have some seawater in your mouth? Then try not to swallow it and put a water bottle in the T1 to rinse your mouth.

Intake

Tolerance (training the gut)

Like your muscles, the stomach is trainable. Not to become more powerful, but to become accustomed to handling large(er) amounts of sugars and passing them on to the small intestine for absorption.

Timing (CHO needs/hour)

It is now generally accepted that, with the right ratio of glucose to fructose, roughly 90 grams of carbohydrate per hour can pass through the stomach and be absorbed by the body. 60 grams of glucose appears to be the absolute limit, which can then be supplemented with fructose to be able to absorb more sugars. Most reputable brands work with this 2/3rds ratio in their gels. Don't just assume you can do this without having practiced on it first.

First, find out if you are fructose-tolerant. Try it out on training. Some individuals do not always respond well to this fast form of sugars. Secondly, build up the volume of sugar intake per hour until you reach 90gr/hour. There are also athletes known to be able to handle up to 100gr or even 120gr of CHO intake. However, this is very exceptional. But they also got there by training. Train your digestive system!

Fuel to moisture ratio

Liquids vs solids

Sugar absorption can come in 2 forms: liquid or solid. Do you have a "shorter" intensive effort on the program? Then opt for liquid. This is digested faster because it often contains "simple" forms of sugars and therefore costs the body less effort to digest. Note: "shorter" is still everything above 1h. Below that it has no added value to take in extra sugar, a mouthwash could have a positive effect.
Solid food ovv a bar or candy can have its uses to appease the stomach a bit, provided the exercise intensity allows it.

Use of medication (NSAIDS)

"Non Steroidal Anti-Inflammatory Drugs" or NSAIDS are well known in the sports environment to treat a minor injury or discomfort. Nothing wrong with that for a race you might think, but be aware that this can have repercussions on your stomach function. Taking a stomach protector with these anti-inflammatory drugs can help. Ibuprofen, diclofenac and naproxen are all examples of NSAIDS.

Caffeine

Caffeine has many ergogenic (read: performance enhancing) benefits can be put to good use during a match, this is not unknown to anyone. However, there is a side note to this: too much caffeine intake can cause.... Yes, gastrointestinal problems.

The important thing here is to train on it and try out different dosages as this is different for everyone. It has been shown that between 3 and 6 mg of caffeine per kg of body weight is the "sweet spot". This gives you the positive effects of caffeine, without too much risk of possible complications. If you tend towards the upper end of this spectrum, the benefits no longer outweigh the possible drawbacks. In addition, for multi-day races you need to think about taking the caffeine on time on day 1, as you don't want to sacrifice sleep quality in the evening because the caffeine prevents a good night's sleep if it is taken short of bedtime.

Coffee is the most well-known source of caffeine. Be aware that there are many other substances present in coffee that can impact your digestive system at higher amounts.

PRO TIP: You can also choose the BYE pro isotonic gel ( 50mg caffeine per gel) or the energy shot (100mg per shot). These supplements contain the necessary caffeine but not the other substances that cause the symptoms.

Macronutrients from daily diet

In endurance sports, certain diets are sometimes used that limit or restrict the intake of carbohydrates. This is done with the aim of stimulating fat burning. The other side of the coin is that the sudden intake of sugars during a race, for example, increases the risk of stomach complaints. After all, you are not used to this from your daily diet. Be careful to "train" your stomach to absorb carbohydrates when you are on such diets. Better yet: let yourself be guided by a nutritionist.

Breakfast on race day

KISS! Keep It Stupid Simple

Don't make it too hard on yourself (and especially your stomach). Choose an easily digestible option, which gives enough energy in the long run ovv slow sugars.

See that there is enough time for digestion (2-3h), but that you don't arrive at the start line hungry either. Stick to foods you are used to and don't try anything new on race day. Light digestible options are: light grains such as white bread, oatmeal, wheat, ... without too much fiber. After all, these only slow down the digestion process. After all, you don't want to start the race on a full stomach. Do not forget to hydrate sufficiently. You can supplement your drink with an isotonic sports drink, which will provide extra electrolytes compared to normal (tap) water.

PRO TIP: Should you be in a very hot environment you can also choose to make this hypotonic, meaning that there is proportionally more fluid per amount of energy in the drink. BYE 's Isotonic sports drink has both isotonic and hypotonic ratios on the jar.

Want to read more about carbohydrates before a race or carbohydrate stacking? Click here for the blog for carbohydrate stacking. or the blog carbohydrates before the race

What to do to avoid this during the race?

Prevention is an absolute concept, that is unfortunately not what it can mean for you I your preparation to the race. Fortunately, most factors can be trained.

If you have figured out what might be at the root of your problem, you can tackle it on and off training. Realize at all times that the above-mentioned factors are not isolated, they are all part of the energy supply from the nutrition to the muscle and will therefore influence each other. We are going to further explain the various factors in chronological order.

Daily diet

We can all imagine that your daily diet has an influence on your sports performance. We won't go into everything that is involved here or give specific advice, for that you can always go to a nutritionist or sports dietitian. What is interesting from your daily diet towards your performance is the total intake in terms of energy, carbo loading to maximize your glycogen supply in your muscles and the amount of fiber you consume until shortly before the race and thus present in the gastrointestinal tract.

An athlete may roughly derive ±50-60% of the total amount of energy from food (kcal or Cal) from carbohydrates. It is important to think about the type of carbohydrates, since sugars are also included. In sport-specific nutrition, sugars have certainly earned their place because of their ideal application (quickly supplying a lot of energy), but in a normal diet it is advisable to choose carbohydrate sources that are not predominantly sugar. You can easily check this in the supermarket by looking at the amount of total carbohydrates and the portion that comes from sugar.

The days before the race you can also apply so-called "carbo loading". This is literally the stacking of carbohydrates, what you do with it is to ensure that the glycogen supply on the muscles (carbohydrates and fats are converted to glycogen before they are used during the effort) to fill to the maximum. See also the following blog about thisProvided you already meet your daily energy requirements in your normal diet, you don't need to eat lots of extra carbohydrates for days on end. Two days before your race a good carbohydrate-rich meal is already enough to maximize the supply. The day before your race you only need to maintain your supply, as the effort is minimal that day, this should be feasible. Stacking two days in advance ensures that you can get rid of the extra "mass" from the digestive tract the day before the race and not take it with you on race day.

During the competition

Think for example of the poor or slow absorption of sugars during heavy exercise. You can train this by taking in food during the intensive blocks in your training in the quantity you are aiming for during the race and you know you can handle it.

Another example is too little fluid intake during the warmer races. For this you need to adjust the sugar/water ratio so that you get enough fluid without overdoing the sugars. Adding extra salts can help in extreme conditions. For this purpose BYE! Nutrition also has a solution in their range that you can take between meals, this is the Magnesium Electrolyte Shot.

If you want to read more related to the triathlon or Ironman see the next page.

Use the code Ironman for 15% off our assortment.

Resources

Causes of stomach problems:

https://www.mysportscience.com/post/what-causes-gut-issues-in-athletes

"Leaky Gut" in heat (link to KONA?)

https://www.mysportscience.com/post/what-causes-an-athlete-s-leaky-gut

Occurrence of:

https://www.mysportscience.com/post/preventing-and-managing-gut-issues

Side step: FODMAP (for LT solution if repeated problem)

https://www.mysportscience.com/post/2017/09/22/low-fodmap-a-novel-tool-prevent-gi-problems

Breakfast on race day: