What to eat before a run?
Fuelling before a run is essential to provide sufficient energy to the whole body, especially the muscles and the brain. Underfuelling can cause symptoms such as early fatigue, cramping, thirst, light-headedness, and the dreadful feeling that you’ve “hit the wall”. How much and what to eat before a run depends on one main factor: how long before the run do you have. Let’s take a closer look at what this means…
How long before the run do you have?
Why does this matter? The simple answer is: digestion. It’s important to allow enough time for your body to digest and process the food you ate before going on a run to avoid gut discomfort. The general rule for digestion is that your body needs on average a full hour to digest a meal. This means that the more time you have before your run (> 1hr), the bigger or more complete your meal can be. With less than 1 hr to digest, it is best to choose small and light snacks.
What should I eat then?
Food provides us energy through 3 different forms: carb, protein, and fat. These three macronutrients also provide us different kinds of vitamins and minerals to stay healthy. There are many differences between them, one being the rate at which it is digested in the body. Protein, fat, and fibre (complex carb) take the longest to digest, while simple carb are quicker to be processed. This means that the closer you get to the start time of your run, you should opt for simple carb and stay away from protein, fat, and fibre.
If you have…
What about hydration?
Water hydrates best. You should drink between 400-600 mL of water in the 2 hours before your run. Build the habit to drink water throughout the day to produce a light-yellow urine colour. Having a hard time drinking water? Add flavor to it such as flavoring drops or slices of fresh fruit or fresh mint leaves!
What to eat during a run?
While our body can use protein and fat as sources of energy, its preferred form of fuel is carb. In fact, the brain alone needs 130 g of carb per day to function! When exercising, the body breaks down carb into glucose for our muscles to use. We also have the ability to stock carb for a later use – this back-up stock is called glycogen stores. If we compare the body to a car, then the fuel tank would be carb (glucose) and a jerry can that you carry along would be glycogen.
The body has enough glycogen stores to sustain moderate exercise for about an hour.
What to consume during your run, depending on duration:
What about hydration during long runs?
Combining water with energy powder is the best way to meet both your hydration and fuel needs. How much water you need to drink depends on several factors such as weather, clothing layers and your individual sweat race. Sips of water are better absorbed than chugging it. Drink at a frequent pace throughout your long run to avoid feeling overly thirsty. When we feel thirsty, our body is already dehydrated by 1-2%. This percentage may seem small, but it has already decreased your performance by 10%!
Practice makes perfect
I will not say this enough: training your gut is as important as training your cardio for long runs. Try different products to find the perfect fit in terms of texture, taste, and energy needs. Some people are more sensitive to high quantity of carb consumed at once and this may cause gut discomfort. Don’t wait until race day to try your nutrition, buy some extras for your training sessions, and test them out!
Anna Ly is a registered dietitian and volunteer firefighter who enjoys working closely with the Yukon community. Anna specializes in sport nutrition and has worked with many local athletes: from recreational to elite, and youth to master athletes. She is currently pursuing a diploma in sport nutrition with the International Olympic Committee (IOC). You can also find Anna providing nutrition services to the francophone community, including the French prenatal program.
Contact her at firstname.lastname@example.org or via her social media platform (@fueled.by.anna) to book an individual sport nutrition counseling session or for a group presentation for your team.