Nutrition & Exercise Part 2: Pre Workout Nutrition

pre exercise fuel

Eating to Perform: fuel your body with carbohydrates.

Exercising without proper nutrition is not ideal. Humor me for a minute and think of your body as a car – pick any kind of car you want. Would you attempt to drive 60 miles when your gas light is on? Would you drive across the country when you are overdue for an oil change or if your tire pressure light came on? If your answer to any of these questions is NO – then you have respect for your car – you want to take care of your car. Guess what folks? The same should go for your body. Afterall, you can’t drive your awesome imaginary car if you get injured during a workout for not eating correctly beforehand. BOOM.

I’m going to run with this whole car example for this blog post. Think of your body as the car engine (more specifically, your muscles are the engine). The engine needs fuel to run. So let’s learn how to fuel our bodies before a workout.


Eating prior to exercise as opposed to fasting has been shown to increase performance. Looking to PR at your next race? Want to score an extra goal or two at the next game? Keep reading.

How Nutrition Optimizes Performance

Nutrition affects your exercise in a big way. Dehydration, electrolyte imbalances, fatigue and GI discomfort are only a few results from improper pre-exercise nutrition. Some athletes will avoid eating, while others will exercise after a large meal – both causing extreme discomfort. Can you imagine trying to run a half marathon while also experiencing hunger pains? No thanks.


  • Fluids! It’s recommended to have 5-7 mL/kg of body weight at least 4 hours before exercise. So that means that a 140# person should have 318-445 ml or ~11=15 oz of water PRIOR to working out
    • trying to figure out how many kilograms you weigh? Take your weight and divide it by 2.2
  • Meals should be low in fat and low in fiber to help decrease GI distress. High-fat foods delay gastric emptying – so it’s sitting in your stomach longer instead of passing through to your intestines for breakdown/absorption. Eating a lot of fiber prior to exercising can make you have to poop.
  • Meals should be low to moderate in protein. Let’s save the protein discussion for a later blog about post exercise nutrition.
  • You also want your meals to be familiar. Eating a brand new type of food right before exercise could leave you running to the bathroom or causing other unwanted side effects.

Carbohydrates: Pre-Exercise Fuel

Meals should be HIGH in carbohydrates (Carbs are the fuel in our car example). Carbohydrates help to maintain your blood glucose (blood sugar) and maximize glycogen stores (stored carbohydrates in your body). We learned in Part 1 that aerobic exercise runs on glycogen stores as energy.

When our glycogen stores are depleted, it causes fatigue and a decrease in intensity, according to a study by Spriet for Sports Med. A diet low in carbohydrates can also negatively impact your central nervous system by messing with your pacing, perception, motor skills and concentration.

Surely most athletes have heard of the term “carb loading”. Carb loading is often an excuse to go to Crazy Town with bread, pasta and a lot of people abuse the term and go off on the donuts, sweets, etc. What do you think is the best way to increase your glycogen stores? Cookies or whole wheat pasta? I’m sure you don’t need my help to answer that one 🙂

But guess what? According to Spriet, any exercise event lasting <90 mintues doesn’t require carb loading. Sorry for ruining anyones day!

The point is: consuming carbohydrates 1-4 hours before exercise is ideal – but don’t go crazy. Be smart with your carbs so you aren’t counterproductive with your workout.

Meal/Snack Examples for Pre-Exercise Nutrition

SCAN – The Sports, Cardiovascular and Wellness Nutrition Dietetic Practice Group I belong to comprised a list of great meal ideas for pre-exercise nutrition:

  • 3-4 hours before exercise
    • Peanut butter & honey toast + fruit + Skim milk
    • Fruit and yogurt smoothie + low-fat granola
    • Oatmeal with brown sugar and almonds + Skim milk + banana
    • Low-fat cottage cheese + apple butter + crackers + grapes
    • Lean hamburger on bun with lettuce and tomato + side salad + yogurt parfait
    • Turkey and Swiss sandwich + fruit + sports drink
    • Low-fat tuna melt sandwich + fruit cup + fat-free yogurt
  • 30-60 minutes before exercise
    • Sports drink or water
    • Piece of fruit or jam sandwich
    • Sports gel, sports bar

Notice that these ideas include some protein in with the carbohydrates. While we are focusing on carbohydrates to be our fuel, we are also taking in some protein to help get us ready for the post-exercise tissue repair.

The big takeaway is this: Practice! Try different timing for eating prior to your meals or different meals to see what works best for you. If you feel like you are dragging during your workouts, start paying more attention to what you are fueling your body with.

Hydration is also huge – but we will get to that soon, I promise 🙂