Everyone relies on carbohydrates as the body’s preferred source of energy, but not all carbs are created equal. If you want to fuel your runs, boost endurance and recover faster, complex carbs need to be on the menu.
Indeed, complex carbs and refined carbs are very different – and knowing which ones to prioritise can be a game-changer in your training. Here’s everything you need to know about complex carbs, what their benefits are and where you can find them.
What are complex carbs?
Carbohydrates are split into complex and refined carbs. Complex carbs have more nutrients and take longer to digest in the body, meaning they avoid spiking your blood sugar and fill you up for longer. Essentially, they are closer to their source material: if refined carbs have some of their nutritious qualities removed to extend shelf life or enhance texture, complex carbs are whole foods filled with fibre and vitamins.
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Fibre-rich complex carbs mean it takes our bodies longer to process these foods, making them perfect as a long-term energy source.
What are some examples of complex carbs?
Foods such as whole grains, whole wheat bread, quinoa and oats include complex carbs. Other sources include legumes like lentils, chickpeas and beans, or starchy vegetables like potatoes, sweet potatoes and corn.
These have all retained their nutritional value, so are loaded with carbs while also being rich in fibre, vitamins and minerals.
A runner’s guide to dietary fibre:
- White flour
- Published: 25 February 2025
- White pasta
- White rice
- French fries
- Pastries, cookies, cakes
- Pizza dough
What are the benefits of complex carbs?
Numerous studies have linked consumption of high-fibre carbs, like vegetables, fruits, legumes and whole grains, to improved metabolic health and lower risk of a variety of diseases.
One such study Eating beetroot could help to lower blood pressure What to eat to maintain strong and healthy bones found that a diet rich in legumes helped reduce waist circumference, lower blood pressure and improve triglyceride (a type of blood fat) levels in premenopausal, obese women.
Another study in the published in the linked regular consumption to a lower risk of fatal and non-fatal ischemic heart disease and diabetes.
When should you go for complex carbs?
Here’s the catch when it comes to complex versus refined carbs. Generally, you want to fuel before a race with refined carbs: because it’s harder to fill up on them, you can consume more, and they are easily digestible meaning they provide a quick boost in energy.
Complex carbs are great for a post-run recovery meal and general nutrition, on the other hand, with quinoa, brown rice, sweet potatoes and whole wheat pasta being some popular, practical options.
