Can I eat in the middle of a workout? The definitive guide to intra-workout nutrition

December 6, 2025 •

4 min read

During intense exercise lasting over 60-90 minutes, your body's stored glycogen can become significantly depleted, causing fatigue and a decrease in performance. Eating strategically during your workout, however, can provide a vital energy boost to prevent this crash and maintain peak output.

Quick Summary

Eating easily digestible carbohydrates during prolonged or high-intensity exercise helps maintain energy levels and delay fatigue. The necessity of mid-workout fueling depends heavily on the activity's duration and intensity. Short sessions typically do not require it, while longer or more demanding efforts benefit greatly from proper intra-workout nutrition.

Key Points

Duration is Key: Mid-workout fueling is primarily for high-intensity or endurance exercise lasting longer than 60-90 minutes, not short sessions.
Prioritize Fast Carbs: Easily digestible carbohydrates like sports gels, drinks, or bananas are ideal for quick energy absorption without causing digestive issues.
Avoid Heavy Foods: Steer clear of high-fat, high-fiber, and large protein meals during exercise to prevent cramping, bloating, and slowed digestion.
Timing Matters: Begin consuming fuel early in longer workouts (e.g., around the 30-45 minute mark) to maintain consistent energy levels.
Never Neglect Hydration: Proper hydration with water and electrolytes is crucial, especially during prolonged exercise, and should always accompany intra-workout fuel.
Experiment in Training: Try different fuel types and timings during practice to find what works best for your body before relying on it during a competition or event.
Consider Your Workout: Endurance athletes have different intra-workout needs than weightlifters, though both can benefit from strategic carbohydrate intake in long sessions.

The Science Behind Mid-Workout Fueling

For many, the idea of eating during exercise seems counterintuitive, often associated with stomach cramps and discomfort. However, for workouts that exceed 60 to 90 minutes or are particularly intense, your body's readily available energy sources are taxed heavily. Our muscles primarily rely on stored carbohydrates, known as glycogen, for fuel. As these stores are used, blood glucose levels drop, and fatigue sets in. Consuming easily digestible carbohydrates during this period helps top up blood glucose, sparing muscle glycogen and sustaining performance. This practice is a cornerstone of endurance training and is increasingly recognized in prolonged strength sessions.

The Duration and Intensity Rule

The need for intra-workout fuel is directly correlated with the length and intensity of your physical activity. Short, low-intensity workouts, like a 30-minute light jog, don't require mid-session fueling. Your body has enough stored energy to get you through without an energy crash. But for activities exceeding an hour, especially those that are vigorous, refueling becomes a strategic necessity. Athletes involved in marathons, long-distance cycling, or extensive high-volume training sessions are the primary beneficiaries of this practice.

What to Eat: Optimal Intra-Workout Snacks

Not all food is created equal when it comes to mid-workout consumption. The key is to choose easily digestible, high-glycemic carbohydrates that your body can absorb quickly without diverting too much blood flow to the digestive system. Fats, proteins, and fiber slow down digestion and are more likely to cause stomach upset during exercise. The goal is to provide a quick and steady source of energy.

Best Intra-Workout Food Sources

Energy Gels and Chews: These are designed for rapid absorption, providing a quick hit of simple carbohydrates. They are highly portable and convenient for endurance athletes.
Sports Drinks: Beverages containing 6-8% carbohydrates and electrolytes can provide fuel and aid hydration simultaneously. They help replenish sugars and lost minerals like sodium.
Bananas: A classic for a reason, bananas offer a mix of simple sugars and are easy to digest. They also provide potassium, a key electrolyte.
Dried Fruit: Options like raisins, dates, or apricots provide a concentrated source of carbohydrates in a small, easy-to-carry package.
Liquid Carbs: Mixing carbohydrate powder like dextrose or maltodextrin with water allows for customized intake, especially during very long sessions.

Intra-Workout Fueling for Different Workouts

The type of workout influences the best fueling strategy. Endurance activities, which rely on a steady energy supply, differ from high-intensity interval training or weightlifting.

Endurance Training: For activities over 90 minutes, aim for 30-60 grams of carbohydrates per hour, and potentially up to 90 grams for ultra-endendurance events. Start consuming fuel 30-45 minutes into the exercise to maintain steady energy levels.
Strength and High-Intensity Training: While not always necessary, an intra-workout shake with fast-digesting carbs and possibly BCAAs can support performance during very long or intense weightlifting sessions, especially when training in a low-carb state or to maximize muscle protein synthesis.

Risks of Eating the Wrong Foods Mid-Workout

Consuming the wrong type or amount of food during exercise can lead to significant gastrointestinal distress and impaired performance. This occurs because the body prioritizes blood flow to working muscles over the digestive system, leaving a full stomach susceptible to discomfort.

Foods to Avoid During Exercise

High-Fiber Foods: Raw vegetables, whole grains, and nuts can sit heavily in the stomach and cause bloating or cramps.
High-Fat Foods: Fatty foods like pastries or fried items digest slowly and redirect blood away from muscles, causing sluggishness and nausea.
Large Protein Meals: While protein is crucial for recovery, large doses mid-workout can slow digestion and cause discomfort.

Comparison Table: Workout Type vs. Fuel Needs


Workout Type	Duration	Mid-Workout Fuel Needs	Best Fuel Choices	Why It's Necessary/Beneficial
Light Jog / Walk	< 60 minutes	Minimal (Water only)	Plain water	Sufficient stored glycogen for activity.
Intense HIIT / Crossfit	< 60 minutes	Minimal (Water/Electrolytes)	Water, electrolyte drink	Body relies on existing glycogen, but electrolytes can help prevent dehydration.
Long Run / Cycle	> 90 minutes	High (30-60g carbs/hr)	Sports gels, chews, diluted fruit juice, bananas	Prevents glycogen depletion and delays fatigue.
Multi-Hour Event	> 4 hours	Very High (Up to 90g carbs/hr)	Liquid carbs, gels, drinks, some whole foods	Sustains extreme energy demands over extended periods.
Long Weightlifting Session	> 90 minutes	Moderate (Carbs + Electrolytes)	Carb powder in water, BCAAs	Delays fatigue, spares muscle breakdown, and aids recovery.

Conclusion: Listen to Your Body

Eating during a workout is not a one-size-fits-all solution, but a strategic tool for athletes and fitness enthusiasts engaging in prolonged or high-intensity activity. For most short, casual workouts, proper pre-workout fueling and post-workout recovery are more than sufficient. However, for sessions lasting over an hour, a timely intake of fast-acting carbohydrates can be the difference between a successful, sustained effort and an energy-depleted crash. Experiment during your training sessions to discover what your body tolerates best. By understanding your body’s energy needs and providing the right fuel, you can optimize your performance, enhance recovery, and take your fitness to the next level. For more detailed information on nutrient timing, consider this comprehensive resource from the National Institutes of Health.

Frequently Asked Questions

If you don't consume carbohydrates during a long, intense workout, your body will eventually deplete its glycogen stores, leading to a phenomenon known as 'hitting the wall' or fatigue. This results in a significant drop in performance and energy levels.

Glycogen is the stored form of glucose in your muscles and liver, and it serves as your body's primary fuel source for high-intensity exercise. When you consume intra-workout carbs, you help spare your limited muscle glycogen stores and keep blood glucose levels stable.

For endurance exercise lasting over 90 minutes, consuming 30 to 60 grams of carbohydrates per hour is generally recommended. For ultra-endurance events, this amount can increase to up to 90 grams per hour.

While protein is important for recovery, consuming large amounts during a workout can slow digestion and cause discomfort. Easily digestible carbohydrate sources are the preferred choice mid-workout. Some athletes use a small amount of protein or BCAAs, particularly during long weightlifting sessions, to help reduce muscle breakdown.

Eating too much, or consuming the wrong types of food, can cause gastrointestinal issues such as cramps, nausea, bloating, and vomiting. This is because blood flow is redirected from the digestive system to the working muscles during exercise.

Endurance training requires a steady, continuous supply of carbohydrates to delay fatigue over a long duration. Strength training's reliance on fuel is more tied to session intensity and length; intra-workout carbs can help support longer, high-volume workouts by sparing muscle glycogen and aiding recovery.

For shorter, low-to-moderate intensity workouts, plain water is sufficient. For longer or high-intensity exercise, especially in hot conditions, a sports drink can be more beneficial as it provides carbohydrates and electrolytes to prevent dehydration and an energy crash.