The Forgotten Carbohydrate Cyclists Need To Know About?

Fibre is a form of indigestible carbohydrate that can play a key significant role in supporting a cyclist’s long-term health and performance but is often a largely unappreciated and understudied component of diet for cyclists.

In this week’s blog, we’ll look at some of the key aspects of dietary fibre and why it’s hugely important for any cyclist who wants to pay attention to it.

What Is Fibre?

First and foremost, Fibre is a form of non-digestible carbohydrate. It typically doesn’t provide any nutrient value in terms of kcals. Still, it has a number of health benefits, from lowering colon cancer risk, reducing cardiovascular disease risk, and lowering low-density lipoprotein cholesterol in the blood. It can also play a key role in the health and function of the digestive system through its interaction with the gut microbiome. The trillions of bacteria within the digestive tract have wide-reaching effects on many systems within the body.

Why Is Fibre Important For Athletes?

As cyclists, fibre is an important consideration for a number of reasons. With the impacts it can have, there are a number of reasons we may look to manipulate the fibre in our diet, which I’ve summarised below…

1. Prevent Stomach Issues During Competition – Fibre plays a really important role in gut health and our overall health, but high intakes of fibre can result in gastrointestinal (stomach) issues in athletes, particularly when cycling in the heat, for prolonged periods or when performing high-intensity exercise. In particular, a group of fermentable carbohydrates called FODMAPS (fermentable oligo-, di-, and mono-saccha-ride and polyols), have to be carefully managed in some individuals as high intakes of these can cause problems. Athletes, therefore, often look to reduce fibre around key races to help prevent gastrointestinal issues. 
   
   
2. Carbohydrate Loading – When athletes look to maximise glycogen stores ahead of a major competition, they do so by eating large quantities of carbohydrates. In this scenario, consuming fibre-rich carbohydrates is likely to leave an athlete feeling uncomfortably full and adding significant bulk to the digestive system, which may prevent an athlete from consuming adequate amounts of carbohydrates; as such, opting for low-fibre intakes during this time can be beneficial.
   
   
3. High Energy Needs – It’s not uncommon for cyclists to expend huge amounts of energy in the region of 3000-6000kcal+ in a single day, and this is on top of an  athletes daily energy needs. To allow an athlete to consume enough energy here, there needs to be focus on energy dense sources of carbohydrates (i.e. sweets, sport gels/drinks/bars) which can displace fibre-rich sources of carbohydrate.
   
   
4. Weight Management – As we’ve covered in a previous blog, when looking for the small margins of performance, improving power to weight ration can be beneficial. Manipulating fibre intake within the diet can help an athlete lose as much a kilogram in body mass in a relatively short space of time, without the need for energy restriction which may impact performance.
5. Appetite management – High fibre foods are often filling. During fat loss phases, athletes can prioritise low energy density, high fibre foods in which to maximise food volume and help manage appetite.

Types of Fibre

There is a large array of different types of fibre, and a key goal to maximise the benefits of these is to eat lots of different fibre-rich whole foods. There are, broadly speaking, two main categories of fibre, insoluble, which simply does change on its way through the gut and soluble fibre, the dissolves in water in the gut and forms a gel-like structure. They can also be classified as fermentable and non-fermatable, with fermentable fibres forming short-chain fatty acids which play additional roles within the body.

How Much Do I Need?

Despite higher energy intakes, meaning that athletes often eat larger volumes of food compared to the general population, many athletes simply don’t get enough fibre in their diets. As yet, we don’t have athlete-specific guidelines for how much fibre an athlete needs, but as a general rule, if well tolerated, an intake of around 30 grams of fibre per day is a good place to aim for. We can get fibre from a whole host of different dietary sources, from wholegrain bread, pasta, cereals and crackers to, beans and pulses, nuts and seeds, dried fruit.

Are you getting enough?

Coach Ben 

References

Mancin, L., Burke, L. M., & Rollo, I. (2025). Fibre: The Forgotten Carbohydrate in Sports Nutrition Recommendations. Sports medicine (Auckland, N.Z.), 10.1007/s40279-024-02167-1. Advance online publication. https://doi.org/10.1007/s40279-024-02167-1