Fibre doesn't get much attention in sport nutrition conversations. Many people think of fibre as ‘roughage’ that can cause bloating and gas. But fibre plays an extremely important role in how our body functions daily. And getting too little of it can affect training, digestion, and even energy levels.

This article will discuss why fibre is important, why it matters for young athletes, and the best ways to get it in. 

What fibre actually does in the body?

Fibre is the part of plant foods the body can't fully digest. It moves through the digestive system relatively intact, which is what makes it so important, because along the way it does a few important jobs: 

• Feeds the trillions of gut bacteria that support digestion and immune function

• Helps keep things moving regularly through the digestive tract

• Slows the absorption of sugar into the bloodstream, helping energy feel steadier rather than spiking and crashing

• Supports a feeling of fullness, which matters for appetite regulation across a busy training day

For a young athlete whose body is managing training, growth, and everything else at once, a well-functioning gut is doing a load of less exciting, but essential work at the same time.

Does fibre get overlooked in young athletes?

Fibre needs don't disappear just because someone is training hard. If anything, a body handling higher volumes of food to meet energy demands benefits from fibre to help regulate it all. But many young athletes may fall short without realising it, particularly when meals may be built around convenience or fussy palates, such as white bread, some breakfast cereals, protein bars, and meat or dairy without much fruit, vegetables, whole grains, or legumes [1,3].

Fibre isn't just found in vegetables. It's present in foods most athletes already eat:

• Wholegrain bread, brown pasta and rice, and oats 

• Fruit with the skin on

• Vegetables at more than just dinner

• Beans, lentils, and chickpeas

• Nuts, nut butters, and seeds

Why gut health matters for performance?

A well-functioning gut isn’t just about keeping your digestion regular. In fact, growing research shows that it's closely connected to our training capacity. Studies increasingly link gut microbiome health to immune function, inflammation, and even our recovery [2,4]. Athletes who deal with frequent digestive issues or a poorly functioning gut may also be more susceptible to getting ill or feeling run down, because a significant portion of immune workings are based in the gut [2].

The timing question: fibre and training don't always mix.

This is where it gets a bit more nuanced, and it's useful to be aware of: although fibre is great for everyday health, a large fibre-heavy meal right before intense training can cause stomach discomfort, cramping, or the need for the toilet [3,4]; Certainly not fun during a match or a tough session.

This doesn't mean avoiding fibre, just being a little smart about timing:

• Higher-fibre meals (big salads, bean-heavy dishes, large portions of whole grains) are ideally better a few hours before training 

• In the 1–2 hours before a session, lower-fibre, more easily digested carbohydrate sources tend to sit better, such as white rice, a banana, or plain toast rather than a big bowl of oats with skin-on fruit and seeds

• After training, fibre can be part of a normal recovery meal

For parents: if pre-competition stomach issues are a recurring issue, it could be worth taking a look at what's being eaten in the couple of hours beforehand. Fibre timing is a common, fixable culprit.

More fibre doesn’t automatically mean better.

Very high fibre intakes, especially if increased quickly, can cause bloating, gas, and digestive discomfort. Additionally, this can make an already-hungry, high-energy-need young athlete feel full before they've eaten enough overall food and calories [1,3]. For a growing athlete with high energy needs, it is not the goal to fill up on fibre if it risks lowering energy intake. The aim is steady, consistent fibre from a variety of whole foods across the week. 

Everyday ways to build fibre in without overthinking it:

• Swap white bread, rice, or pasta for whole grain versions most of the time

• Add fruit to breakfast and a vegetable to lunch and dinner

• Keep fruit as a normal snack, skin on where it makes sense (apples, pears, grapes)

• Add beans or lentils into meals that already exist, such as a bolognese, a curry, a wrap 

• Snack on nuts or seeds alongside other food, especially around longer gaps between meals

• Find fun ways to add more fibre into your meals, like this bounty overnight chia seed pudding
  
  

• Or Butter Bean Gnocchi (videos be

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Takeaway message: Fibre may not be the most exciting part of a young athlete's plate, but it impressively supports digestion, gut health, immune function, and steady energy throughout the day. Having a consistent base of whole foods across the week, with a bit of common sense about what goes in right before a session for the rest of the day.

Checklist for parents and athletes

• Build meals around whole grains, fruit, vegetables, and legumes most of the time

• Save the bigger fibre-heavy meals for a few hours before training to avoid mid-training discomfort 

• Keep pre-training snacks simple and easy to digest if training is within an hour or two

• Don't fill up on fibre if it means not eating enough overall

• Keep whole grain versions of bread, rice, and pasta as the default at home

• Have enjoyable fruit and vegetables easy to grab 

• If pre-training stomach issues come up often, look at what's eaten in the couple of hours beforehand

• Remember fibre supports the training, but total food intake still comes first

Disclaimer: This article is intended to provide general information about nutrition for youth athletes and is not meant to replace professional dietary advice or individual nutritional counselling. Fibre needs and tolerance vary from person to person. If digestive symptoms are persistent, severe, or concerning, please speak with a doctor or registered dietitian.

References

[1] Anderson JW, Baird P, Davis RH, et al. Health benefits of dietary fiber. Nutrition Reviews. 2009;67(4):188–205. https://doi.org/10.1111/j.1753-4887.2009.00189.x

[2] Clark A, Mach N. Exercise-induced stress behavior, gut-microbiota-brain axis and diet: a systematic review for athletes. Journal of the International Society of Sports Nutrition. 2016;13:43. https://doi.org/10.1186/s12970-016-0155-6

[3] Desbrow B, McCormack J, Burke LM, et al. Sports Dietitians Australia position statement: sports nutrition for the adolescent athlete. International Journal of Sport Nutrition and Exercise Metabolism. 2014;24(5):570–584. https://doi.org/10.1123/ijsnem.2014-0031

[4] de Oliveira EP, Burini RC, Jeukendrup A. Gastrointestinal complaints during exercise: prevalence, etiology, and nutritional recommendations. Sports Medicine. 2014;44(Suppl 1):79–85. https://doi.org/10.1007/s40279-014-0153-2