Some people feel their best after a solid pre-workout meal. Others prefer to exercise on an empty stomach. The truth is, there is no one-size-fits-all answer. But science does give us some helpful guidance.
The Case for Eating Before Exercise
Eating 1 to 2 hours before you work out can boost performance, especially if the meal includes a good mix of carbohydrates, protein, and a little healthy fat. Carbs provide quick energy for your muscles. Protein and fat help slow the release of sugar into the blood, which may keep your energy steady and delay fatigue during intense training (1)†.
The timing matters. Eating too close to your workout can cause discomfort or nausea for some people. This is why many find a light meal or snack works best. Listen to your body’s signals, and experiment to find your sweet spot.
How Meal Type Affects Your Body
The makeup of your pre-workout meal can change how your body responds. A 2023 study found that high-carb and high-fat meals can affect appetite hormones differently, as well as change insulin sensitivity after exercise (2).
High-carb meals may give you a quick energy burst, but can lead to a faster drop in blood sugar.
Balanced meals, with carbs, protein, and fat, can keep energy stable and help with muscle repair.
Higher-fat meals can slow digestion, which might be helpful for endurance events, but may feel heavy before shorter workouts.
Fasting and Morning Workouts
If you train in the morning, you might wonder if it’s worth eating first. For most healthy people, fasting before a short workout doesn’t drastically affect blood glucose in the short term. However, for those with type 2 diabetes, research shows that exercising after a meal can help lower insulin levels, which may support better long-term blood sugar control (3).
What About GI Discomfort?
Eating too close to a workout can increase the risk of gastrointestinal (GI) issues. When you eat, blood flow moves toward your digestive system. Exercise redirects that blood toward your muscles, which can slow digestion and lead to problems such as:
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Stomach cramping or bloating
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Nausea, especially after large or high-fat meals
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Acid reflux or heartburn, often worse with bending or lifting
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Urgency to use the bathroom, particularly with high-sugar foods, sugar alcohols, or caffeine (endurance sports like running and cycling are notorious for this “runner’s gut” effect.)
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Side stitches during running or other high-impact activities
To lower your risk, aim for a smaller meal 1–2 hours before training, keep fat and fiber lower, and choose foods you know your body digests well. Adjust timing based on the workout’s length and intensity.
So, Should You???
Small, nutrient-dense meals before exercise are generally safe and may support muscle protein synthesis and heart health when combined with regular physical activity (4)†. Your approach should match your goals, workout intensity, and comfort level.
For most people, eating a light, balanced meal before working out is a good choice. But if you enjoy fasted exercise and it works for you, there’s no strict rule against it (5). Pay attention to your performance, recovery, and how you feel, and let that guide you.
† These statements have not been evaluated by the Food and Drug Administration. This content is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
Relevant Studies
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Fister, I., & Fister, D. (2018). Sports Nutrition.. Current developments in nutrition, 2 11, nzy052 . https://doi.org/10.1093/cdn/nzy052.
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Almesbehi, T., Edwards, C., & Malkova, D. (2023). The influence of macronutrient composition of meals consumed the day before and the day including morning exercise session on gastrointestinal appetite hormones and post-meal insulin sensitivity in overweight men. Proceedings of the Nutrition Society, 82. https://doi.org/10.1017/s0029665123002987.
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Bravo-García, A., Radford, B., Hall, R., Broome, S., Tee, N., Arthur, B., Janssens, K., Johnston, R., Halson, S., Devlin, B., Hawley, J., & Parr, E. (2025). Combined effects of Time-Restricted eating and exercise on short-term blood glucose management in individuals with type 2 diabetes mellitus: The TREx study, a randomised controlled trial.. Diabetes research and clinical practice, 112081 . https://doi.org/10.1016/j.diabres.2025.112081.
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Kinsey, A., & Ormsbee, M. (2015). The Health Impact of Nighttime Eating: Old and New Perspectives. Nutrients, 7, 2648 - 2662. https://doi.org/10.3390/nu7042648.
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Regmi, P., & Heilbronn, L. (2020). Time-Restricted Eating: Benefits, Mechanisms, and Challenges in Translation. iScience, 23. https://doi.org/10.1016/j.isci.2020.101161.
