Ask the Nutritionist: What Should I Eat Before I Exercise?

Written By: Beth Zenke


The short answer: It varies.


Most athletes and every day exercisers underestimate the importance of pre-exercise fueling. The benefits of a pre-exercise meal are multi-faceted. Pre-exercise fueling helps maintain blood glucose levels to avoid hypoglycemia (low blood sugar), which negatively impacts performance. The right food choices can also alleviate upper gastrointestinal (GI) discomfort by absorbing gastric juices, can fuel your muscles via glycogen production and storage, and fuel your brain, all of which allows for increased performance and a higher calorie burn.


What you should eat is highly dependent on the duration of exercise.


For activities lasting less than 90 minutes, carbohydrates are your friend. Having a ripe banana, blueberries in low-fat yogurt, or a granola bar and milk will allow your body to quickly digest the snack and turn it into useable energy. Consume this pre-exercise meal or snack at least 90 minutes prior to the event.


Note: Protein and fats should be avoided in these instances as they delay gastric emptying, delaying the time between digestion and increased blood glucose levels. High fiber foods should also be consumed with caution as they stay in the stomach longer, which can lead to upper GI distress, such as heartburn and vomiting.


For activities lasting longer than 90 minutes, think half marathons or century bike rides, adding fat and protein will support sustained performance. While the fact that protein and fat delay gastric emptying and, in turn, decrease the rate of digestion is a problem for those shorter bursts of activity, it actually helps in these situations because these meals fuel the body over longer periods of time. Try a bagel with 2 T of any nut butter and a latte, a cheese omelet with toast and milk, or granola with full fat yogurt and berries or a banana. Timing of this type of pre-exercise meal is a little more personal and depends on your tolerance and digestive rate. Aim for at least three hours prior to the event to give the stomach time to digest and empty.


Like most things in life, each athlete needs to learn what works best for them. Keep a food log as you train for a big event to be sure you fuel with foods that you tolerate best. Play with the timing of meals and snacks to see how your performance reacts with different amounts and types of energy available. And finally, don’t forget the pre-exercise hydration!







Beth Zenke

Beth's active childhood matured into three sports a year in high school, which turned into a lifelong love for fitness and health. After a serious health scare her freshman year of college, Beth decided to pursue a degree in nutrition. She completed a degree in human biology with an emphasis in nutrition at the University of Wisconsin- Green Bay and a post- baccalaureate internship at Mount Mary College. After passing the registration exam, Beth became a Registered Dietitian Nutritionist (RDN). She then accepted a position at the Veterans Affairs hospital in Milwaukee where she primarily worked in Oncology helping cancer patients during and after treatment. These experiences convinced Beth that healthy eating can fit into anyone's life, but it doesn't look the same for any two people. A healthy lifestyle needs to be tailored to each individual's wants, needs, and beliefs.

Along with her passion for healthful food choices, Beth believes remaining active is crucial to a healthy lifestyle. Beth has completed numerous half marathons. Her daily commitment to fitness is supplemented as often as possible with active, adventurous travel experiences; she's jumped in the water to explore the Great Barrier Reef and hiked the Incan trail to Machu Picchu in Peru, tackled Mount Teide in the Canary Islands, and enjoyed the differing terrain of the Tetons and Yellowstone.

Beth has enjoyed indoor and outdoor cycling for over a decade. After having her first daughter, her workouts moved primarily indoors, which is when she discovered her love for a good cycling class. Building on those experiences, Beth's own classes focus on differing intensities and drills that keep the mind occupied while the legs produce some major power. She believes music can truly motivate a person to push to their full capability and welcomes any and all requests.

Beth and her husband Ryan live in Glendale with their two young daughters: Laura and Anneliese. She enjoys cooking, traveling, and spending time with family and friends.

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The thoughts and information set forth on this website are not intended to provide medical advice and are not intended to treat, diagnose, or prevent any disease or ailment. The material provided on this website is for informational purposes only and should never be used in lieu of formal medical diagnoses or treatment with a qualified physician. All individuals should undertake a complete physical before commencing any diet, exercise or health program.