Nutrition During Sport: Amping Up Performance


by Lisa Podlecki, RD, Diploma Sport Nutrition IOC

While plenty of attention is typically paid to pre- and post-workout nutrition, what you eat during a workout or race can also have an impact on your performance. For example, have you ever felt faint, light-headed or dizzy during a workout? Have you been unable to focus or concentrate? Do you find that your pace decreases during the second half of a race? Have you experienced a sudden loss of energy or “hitting the wall?” If any of these symptoms resonate with you, or you want to take your performance to the next level, consider trying the strategies below.

Why would I eat during my workout?

Nutrition during training can improve your energy, increase your mental focus, and provide physical comfort (i.e. not feeling hungry). The best way to do this is by staying hydrated and making sure your body has enough carbohydrate. Carbohydrates are the most efficient fuel source we use during exercise. When we’re physically active, our body taps into the stored form of carbohydrate known as glycogen. Therefore, ensuring you have enough carbohydrates before a quality training session would be the first strategy to maximize performance.

In addition, if the exercise is consistent for more than one hour and is of moderate to intense activity, our body runs out of glycogen and we need to add more carbohydrate. This is crucial if your goal is to maintain the same pace, intensity and focus throughout the session.

How do I know if this concept applies to me?

Whether you should eat (and how much) really depends on the duration and intensity of the session. As a general guideline, it is recommended to add carbohydrate during any moderate to high intensity activity longer than 60 to 90 minutes. Here is a summary:

What should I eat and drink?

Once you’ve identified what is needed for your training level, the next step is to figure out what works best for you. Training your gut to tolerate nutrition is just as important as training your muscles and lungs for a race. It is highly recommended to test foods and liquids as soon as possible while training (i.e. on your long runs) so you can have these same foods during your race. Just as you would not wear new, unfamiliar shoes in a race, you do not want to try any new foods or liquids on race day.

During the workout or race, you should aim for 5 to 10 ounces (60 to 120 mL) of fluid every 20 minutes, or 2 to 4 cups (500 mL to 1 L) every hour. This is just a general guideline, since it really depends on the conditions and your individual sweat rate. In addition, you should be taking in some carbohydrates every 15 to 20 minutes.

While some people can tolerate regular food during exercise, most runners find it easier to digest foods like gels, sports drinks, fruit purées and chews. Here are some examples that provide approximately 30 grams of carbohydrate:

  • 500 mL sports drink
  • 6 GU chews
  • 1 sports gel
  • 5 pieces of dried mango
  • 2 pouches of baby food purée

What about electrolytes?

If you are exercising for more than two hours, sweating heavily, or running in very hot conditions, an electrolyte supplement may be needed. Sodium is the main electrolyte lost in sweat, and since sodium is a component of salt, the terms are sometimes used interchangeably.

A good way to tell if you are a “salty sweater” is if you notice white marks on your clothing (or white crystals on your skin) after working out. While it is unlikely that you are at risk of a sodium imbalance if you are exercising for less than four hours, having a bit of sodium (salt) during exercise will help you stay hydrated. Try adding about a quarter teaspoon of salt to 1 litre of water, or carry a 500 mL sports drink. If you are able, you can try snacking on salty food during the race.

In conclusion, while it might seem strange to eat during a workout or race, nutrition during exercise will make a difference to your energy level, focus and overall performance. Remember, practice makes perfect! Train your gut to start tolerating foods and liquids during your activity. Find out what works best for you and stick to that plan on race day.

Lisa Podlecki is a Registered Dietitian and Sports Nutritionist in Edmonton. Lisa loves helping individuals meet their nutrition goals in a healthy and sustainable way and regularly speaks at the Running Room training programs. For more information, visit her website at (Bio photo: Kaihla Tonai Photography)

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