Have you ever thought about the role of your gut on sports performance? Your gut allows fluids and carbohydrates (main source of fuel) to be absorbed and delivered during exercise. Throughout this article, the association between microbiome and sports will be explored. We will also dive into an adaptative mechanism that may improve endurance performance – i.e., “training the gut”.
Gut Microbiome and Sports Performance
Our gut is the household of multiple microorganisms, some of which are beneficial to our overall health. The composition of gut microbiome is established during birth, being highly diverse and dynamic between individuals. Throughout life, gut microbiome is dependent on different factors, including age, stress, smoking, drugs usage (mostly antibiotics), and diet.
Regarding exercise, evidence has been less described – even though some studies present an association between sports and gut microbiome, there is still a need for longitudinal and experimental studies. However, some mechanisms that show a linkage have been described in the literature.
When a complex carbohydrate is ingested, it is digested and broken down through fermentation by gut bacteria. Consequently, short-chain fatty acids (SCFA), such as propionate and butyrate, are produced. SFCA are important for various vital functions in the organism. Particularly, butyrate and propionate seem to act as fuel for muscles and gut lining cells.
A study conducted in amateur and professional cyclists found that a higher exercise duration was linked to higher levels of Prevotella, a bacteria involved in carbohydrates and amino acids metabolism. Other bacteria that deserves attention regarding this topic is Veillonella, which metabolizes lactate – a metabolite of anaerobic respiration associated with muscle soreness. As so, Veillonella may act as an aid of exercise capacity and recovery.
Gut microbiota has also a role in hydration status, being involved in electrolytes transportation through gut lining cells. Similarly, gut health has a role in hormones regulation, namely cortisol, serotonin, and GABA – these hormones may impact sleep quality. As it is known, sleep quality may impact sports performance.
Probiotics are living organisms that have many health benefits and may improve the composition of your gut bacteria. There are different species of probiotics (e.g. bifidobacterial or lactobacillus), and each specie has subtypes, known as “probiotic strains”. On its turn, each probiotic strain has diverse roles on the organism. Some of these strains are not scientifically studied and validated – since benefits are dependent on the chosen strain, caution must be taken when choosing this type of supplements. Specific strains might promote sports recovery, but more studies are needed.
Given its role on energy metabolism, immunity and gastrointestinal health, gut microbiota likely presents itself as essential for health, wellbeing, and performance of athletes. But how can diet improve gut health?
Diet modulates microbiota activity and composition. An increased fibre consumption is associated with a richer microbiome. A higher intake of carbohydrates and dietary fibres seems to be associated with higher levels of Prevotella. Protein also seems to promote microbiota diversity – however, more studies are needed.
In general, a diet rich in polyphenols, prebiotics and fibre may promote microbiome diversity. This includes nuts, pulses, fruits (such as berries), seeds, vegetables, whole grains, dark chocolate, and fermented foods (kefir, yoghurt, kombucha, sourdough bread). Highly processed foods can increase pathogenic organisms – as so, this type of foods must be avoided.
“Training the Gut”
Gut is responsible for delivering nutrients that are essential to exercise performance, such as carbohydrates and fluids. Moreover, in many sports (especially endurance) gastrointestinal symptoms (such as vomiting, diarrhoea and bloating) arise. Similarly to muscles, our gut is trainable and adaptable. Consequently, we must find strategies to augment nutrients delivery (promoting performance) while minimizing gastrointestinal symptoms.
As explored in this article, different mechanisms can be used in order to “train the gut”. We advise you to read it before advising or following this approach:
- Training after drinking large volumes of fluids (“train the stomach”);
- Training immediately after a meal;
- Training with high carbohydrate intakes during exercise;
- Simulate the exercise with an exercise nutrition plan;
- Increase carbohydrate content of the diet.
Gut health must be promoted through diet and lifestyle. A “health-associated” microbiota may improve athletes wellbeing and performance, both directly and indirectly. As so, it is advised to consume whole grains, fruits, vegetables, nuts, pulses, and also fermented foods, which are rich in probiotics. Highly processed foods should be avoided. For endurance athletes, approaches that minimize gastrointestinal symptoms and allow nutrients delivery (such as “training the gut”) can also be considered.
The content of this article does not constitute medical advice by a registered healthcare professional. Please consult your physician before starting any new diet, exercise or training programme.