Gut Health and Athletic Performance

by Ashleigh Feltham,  Accredited Practising Dietitian and Accredited Nutritionist

There’s an important synergy between gut health and athletic performance. An athlete’s diet plays a critical role in contributing to optimal performance and results. The diet of an athlete is often very different to the average person. An example includes more refined carbohydrates and less fibre to provide quick fuel to the muscles for performance. Including high fibre choices during sport is not recommended due to a slowing of gastric emptying and may cause gut upset.

Outside this period of time when high fibre is not recommended, it is still important for an athlete to achieve adequate fibre intake. If the diet lacks sufficient fibre, there may be poor health outcomes. This includes the reduced health of the gut and consequently performance may be negatively affected.

Picture of an athlete at the running track

A healthy gut microbiome is as unique to every person as a fingerprint. An optimal gut microbiome is made up of different amounts and types of microbes. Your diet determines what types and amounts of microbes live and flourish in your gut. These gut microbes send messages which directly and indirectly effect the health of your entire body.

An athlete’s diet is typically high in protein, often animal based protein, low in fibre and devoid of certain foods. This avoidance of certain foods can limit the variety in a diet. This consequently negatively impacts your gut microbiome by causing an imbalance of the types and number of microbes in your gut. The types of messages which are sent from your gut microbes alters and causes ill health consequences throughout your body. Gut dysbiosis negatively impacts your immune system by decreasing its ability to function at an optimal level.

When your gut microbiome is out of balance it can also reduce the ability of your gastrointestinal tract to function. This negatively impacts performance in many ways including reducing the ability of your gut to process the food you eat to create fuel essential for athletic performance. Additionally, gut dysbiosis can decrease the ability of the gut to cope with high intensity exercise.

To promote optimal health and performance, a diet that contains enough of a variety of fibre, as well as food sources containing probiotics, prebiotics and synbiotics is essential. Also necessary is a variety of protein including plant-based sources, and unsaturated fats, in particular omega-3, an essential polyunsaturated fat.

An adult needs between 25g and 38g of dietary fibre each day. This can be achieved through including a variety of plant-based foods in meals and snacks like wholegrains, vegetables, fruit, nuts, seeds, legumes and beans. In addition to including a variety of plant-based foods, the South Australian Gourmet Food Company Fruit Custard with Added Fibre is a smart addition to your diet to help meet this dietary fibre target. Each delicious custard is long-life and easily transportable. Available in Strawberry, Banana and Apple, each custard contains 11g of dietary fibre.

girl drinking smoothie

Take home message – Gut Health and Athletic Performance:

The diet of an athlete during training and competition does need to be adjusted from an average person’s diet to meet energy demands and limit gastrointestinal upset during activity. In saying this, the overall diet of an athlete still requires adequate fibre, unsaturated fat, prebiotics, probiotics and symbiotics to ensure a healthy gut microbiome. This will not only positively impact overall health but also improve performance.



  1. Riley L Hughes, Hannah D Holscher, Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise, and the Gut Microbiota in Athletes, Advances in Nutrition, Volume 12, Issue 6, November 2021, Pages 2190–2215,
  2. Lavelle, A., Sokol, H. Gut microbiota-derived metabolites as key actors in inflammatory bowel disease. Nat Rev Gastroenterol Hepatol 17, 223–237 (2020).