Grains 101: what to tell your athletes about carbs
An athlete corners you right before a session: "Should I even be eating carbs today?" It's a fair question, and one you'll probably get more than once. Half the internet says carbs slow you down. The other half says you can't train hard without them. Here's the short, science-backed version you can actually repeat: your athlete needs carbs to perform, and knowing why makes the conversation a lot easier.
What are carbs exactly?
Before we dive into why athletes need carbs and what carb sources look like, let's talk about what carbs even mean. Carbohydrates (carbs, to keep it short) are the body's driving fuel, one of the main macronutrients the body needs, alongside protein and fats. They come in three forms: sugars, starches, and fibre. Sugars and starches both break down into glucose, fibre mostly doesn't, which is exactly why fibre behaves so differently around training (more on that later).
Once eaten, carbs get broken down into glucose, the only fuel the brain runs on almost exclusively and a key fuel source for working muscles. Some of that glucose is used right away for energy, and the rest gets stored as glycogen in the muscles and liver, ready to be tapped into once the body needs more fuel than what's circulating in the blood.
Exactly how much an individual athlete needs depends on their training load and goals, that's something the FoodCoach app already calculates per athlete, so it's not something you need to work out by hand.
Why do athletes need carbs?
For most people, carbs are just an energy source. For athletes, they're closer to performance fuel, and the science behind why is more interesting than "carbs give energy."
- Fast energy source: Carbs are the body's predominant and most efficient source of energy, especially for moderate- to high intensity activities like an HYROX endurance session.
- Maintain stable blood sugar levels: Carbs are rapidly converted into glucose, which is transported in the blood known as blood glucose or blood sugar. Glucose can also be stored in the body as glycogen, in the liver and muscles. Eating carbs before your workout increases glucose in the blood and may increase glycogen content. This can help prevent a rapid drop in blood glucose levels, reducing the risk of symptoms such as dizziness, lightheadedness, and a drop in performance during training.
- Delay fatigue: Adequate glycogen stores in the liver and muscles are crucial for delaying the onset of fatigue. Eating carbs before your workout can optimize these glycogen levels and therefore maintain optimal performance.
- Mental focus: Running low on carbs doesn't just tire the legs, it tires the brain that's driving them. When muscle glycogen runs low, blood glucose tends to drop with it. Because the brain depends so heavily on glucose, that drop hits the central nervous system directly, affecting motor drive and motivation to keep pushing, not just the muscles themselves. Consuming carbs before your training therefore also supports mental clarity and focus during your training.
How to get your carbs in?
Grains are one of the most practical carb sources out there: accessible, versatile, and easy to build a plate around. But not every grain plays the same role around a training session.
The fibre in whole grains is great for the rest of the day. It slows digestion, which helps keep blood sugar and energy stable and supports concentration and appetite regulation between sessions. Right before an intense session, though, that same slow digestion can work against an athlete: a high-fibre meal takes longer to turn into usable fuel and sits heavier during exercise. So the closer you get to training, the more it pays to reach for lower-fibre, quicker-digesting grain sources, and save the whole grains for meals with more recovery time around them.
- Around training (right before, or straight after): lower-fibre, easily digestible sources such as white rice, white bread, or a tritordeum-based option built for quick digestion.
- Everyday meals, with time to spare before or after training: whole grain options like oats, wholegrain bread, quinoa, or wholewheat pasta, for their fibre and steadier release of energy.
Curious how this plays out in practice? Our knowledge partner GrainLabs digs into the science of grain-based fuelling on GrainLabs.nl, and you can read more on how sustained energy from grains supports training consistency in Grainlabs: Sustained Energy.
The takeaway
Carbs aren't the enemy, they're the fuel. The question for an athlete isn't "carbs, yes or no," it's which grain, and when. Save the whole grains for the meals with room to digest, and keep the quicker-digesting sources close to training. Next time an athlete asks, you've got the answer. And if you want the exact numbers for their training load, the FoodCoach app already has them calculated.
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GrainLabs is a knowledge centre where consumers, grain processors, scientists, healthcare professionals, and sports experts share knowledge and collaborate to allow grains to flourish optimally in our diet. After all, nutrition is the most important element for improving our body's performance.
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