Is it good to have protein during a workout? A look into intra-workout nutrition

December 19, 2025 •

5 min read

According to the International Society of Sports Nutrition, while total daily protein intake is most critical for muscle adaptation, consuming protein before and/or during prolonged exercise can stimulate muscle protein synthesis and improve training efficiency. This evidence sheds light on whether it is good to have protein during a workout, suggesting potential benefits for certain training scenarios.

Quick Summary

This article explores the science behind consuming protein during a workout, detailing the specific contexts where it can benefit muscle recovery and endurance. It clarifies the role of intra-workout nutrition, distinguishing between fast-acting amino acids and whole protein, and addresses the potential downsides of eating during exercise. Recommendations are provided for various athletes based on training duration and intensity.

Key Points

Not always necessary: For workouts under 60-90 minutes, a proper pre-workout meal provides sufficient fuel, making intra-workout protein often unnecessary.
Beneficial for long/intense sessions: Athletes engaged in prolonged, high-intensity exercise can benefit from intra-workout protein to sustain energy and minimize muscle breakdown.
Focus on amino acids: Fast-digesting amino acids (BCAAs/EAAs) are better for intra-workout use than slower-digesting whole proteins to prevent GI distress and provide immediate fuel.
Combine with carbs: Pairing protein with fast-digesting carbohydrates and electrolytes is an effective strategy to maintain energy, hydration, and performance during long workouts.
Total daily intake is key: More important than the precise timing of protein during a workout is meeting your total daily protein needs, consistently and strategically distributed throughout the day.
Listen to your body: The optimal strategy varies by individual. Experiment with different intra-workout approaches during training to find what works best for your body's tolerance and goals.

The Science of Intra-Workout Protein: Who Benefits Most?

For most people engaging in standard, sub-60-minute workouts, consuming a pre-workout meal rich in carbohydrates and protein is sufficient to fuel the session and kick-start recovery afterward. However, for those performing intense or prolonged exercise lasting 90 minutes or longer, introducing nutrients during the workout—known as intra-workout nutrition—can offer distinct advantages. This practice can help sustain energy levels, prevent muscle protein breakdown (catabolism), and accelerate the recovery process. The type of protein consumed also matters, with fast-digesting options like branched-chain amino acids (BCAAs) or whey protein hydrolysate being more suitable than slower-digesting whole foods, which can cause digestive issues during exercise.

Amino Acids vs. Whole Protein: A Breakdown

When considering intra-workout protein, the choice often comes down to pure amino acids versus a complete protein source. While complete proteins are essential for overall dietary needs, fast-acting amino acids offer specific advantages during exercise.

Amino Acid Supplements (BCAAs/EAAs):

Faster Absorption: BCAAs (Leucine, Isoleucine, Valine) and EAAs (Essential Amino Acids) do not require extensive digestion and are absorbed quickly into the bloodstream. This makes them ideal for immediate use by the muscles during a workout.
Preventing Catabolism: Providing a direct source of amino acids helps mitigate exercise-induced muscle protein breakdown, especially during fasted training or periods of caloric restriction.
Delaying Fatigue: BCAAs compete with tryptophan for entry into the brain, which can help combat the onset of fatigue and improve focus during long sessions.

Whole Protein (e.g., Whey Powder):

Complete Profile: Offers all 20 amino acids needed for comprehensive muscle repair and synthesis.
Slower Digestion: Digestion is a slower process, which can divert blood flow to the stomach and potentially cause gastrointestinal discomfort during intense exercise.
Less Suited for Intra-Workout: While effective post-workout, its slow digestion makes it a suboptimal choice for consuming mid-session for immediate fuel and performance.

The Role of Intra-Workout Carbs and Electrolytes

Protein should rarely be consumed alone during a workout, as the body's primary fuel source for high-intensity exercise is carbohydrates. A common and effective strategy is to combine protein with fast-digesting carbohydrates and electrolytes to create a complete intra-workout fuel source.

Carbohydrates for Energy: Intra-workout carbohydrates, such as maltodextrin or dextrose, help maintain blood glucose levels and replenish muscle glycogen, delaying fatigue and sustaining performance. Studies on endurance athletes, for example, show significant improvements in performance when consuming a carb-protein mix.
Electrolytes for Hydration: Sweating causes a loss of vital electrolytes like sodium and potassium, which are essential for muscle contractions and nerve function. Adding electrolytes to your intra-workout drink is critical for maintaining hydration, preventing cramps, and optimizing performance, particularly during high-intensity or hot-weather training.

Comparison Table: Intra-Workout Scenarios


Training Duration & Intensity	What to Consume During Workout	Why It Works
Short (<60 mins)	Water or electrolyte drink.	Energy stores from pre-workout meal are sufficient; the focus is hydration and mineral balance.
Moderate (60-90 mins)	Electrolyte drink with minimal carbs.	Provides light energy boost and prevents dehydration without overloading the digestive system.
Long & Intense (90+ mins)	Carb and BCAA/EAA mix.	Delays fatigue, minimizes muscle breakdown, and sustains energy levels by topping off glycogen stores.
Fasted Training	BCAA/EAA supplement.	Prevents muscle catabolism and supplies immediate amino acids for energy without breaking a fast.
Endurance Racing	Carb and protein solution.	Supports continuous energy supply and delays fatigue, with some evidence of reduced muscle soreness post-race.

Potential Downsides and Considerations

While there are clear benefits for specific athletes and training types, intra-workout protein is not without potential downsides. For casual gym-goers, the added protein is often unnecessary and could lead to excess calorie intake. In addition, relying too heavily on supplements can cause you to neglect obtaining a balanced protein intake from whole food sources throughout the day, which is arguably more important for long-term progress. Digestibility issues are also a concern, as some athletes may experience stomach upset, bloating, or cramping from ingesting supplements during high-intensity activity. It is important to experiment during training sessions to find what works best for your body. Lastly, while concerns about high protein intake causing kidney damage are largely unwarranted for healthy individuals, those with pre-existing kidney conditions should always consult a doctor before increasing protein consumption.

How to Strategize Your Intra-Workout Fuel

For most athletes, especially those engaged in standard-length workouts, the primary focus should be on proper pre- and post-workout nutrition, with adequate daily protein intake being the most important factor for muscle growth and recovery. Intra-workout supplementation is a tool best used strategically for specific scenarios. For instance, an ultra-endurance athlete or a bodybuilder completing a multi-hour session will benefit far more from a carb-protein blend during their workout than someone doing a casual 45-minute gym session. The key is to match your nutritional strategy to the demands of your training and personal goals.

Conclusion: Optimizing Your Training With Intra-Workout Protein

Whether it's good to have protein during a workout depends on the intensity, duration, and type of exercise. For most, total daily protein intake is paramount, but for athletes engaged in prolonged, intense training or fasted workouts, strategic intra-workout protein or amino acid supplementation can offer tangible benefits. These include stimulating muscle protein synthesis, preventing catabolism, and delaying fatigue. By prioritizing carbohydrates for energy and electrolytes for hydration alongside fast-digesting protein sources, specific athletic goals can be optimized without causing digestive distress. Ultimately, listening to your body and aligning your nutrition with your training demands is the most effective approach to maximizing performance and recovery.

The International Society of Sports Nutrition's Position on Protein

The International Society of Sports Nutrition (ISSN) provides comprehensive guidelines on protein and exercise. A detailed reading of their position stand offers valuable, evidence-based insights into dietary protein requirements and timing for physically active individuals, solidifying the importance of adequate and appropriately timed protein intake for optimizing training adaptations.

Intra-Workout Nutrition: Final Takeaways

Protein is not essential for all workouts, but can be beneficial for specific scenarios.
Intense, prolonged exercise (90+ minutes) or fasted training are prime candidates for intra-workout protein.
Prioritize fast-digesting amino acids (BCAAs/EAAs) over whole proteins during a workout to avoid GI issues.
Pair protein with carbohydrates and electrolytes to provide a complete fuel source and enhance hydration.
For most, focus on meeting total daily protein goals through a balanced diet, with supplements used strategically as needed.

Frequently Asked Questions

No, it is not inherently bad, but for most standard workouts, it is unnecessary. The main concern is digestive discomfort, as blood flow is diverted from the stomach to the working muscles during intense exercise. For prolonged, high-intensity training, consuming fast-digesting protein like BCAAs can be beneficial.

The best kind of protein for consumption during a workout is in the form of fast-absorbing amino acids, such as BCAAs or EAAs, or a hydrolyzed whey protein. These options require minimal digestion and can be utilized quickly by your muscles, unlike slower-digesting whole food proteins.

For specific athletic scenarios, yes. Studies show that intra-workout protein can stimulate muscle protein synthesis and reduce muscle breakdown, particularly during prolonged endurance training or resistance training sessions lasting over 90 minutes. However, their impact on acute performance is less clear when sufficient carbohydrates are consumed.

While technically possible, a regular whey protein shake is not the best choice for intra-workout fuel. Whole proteins require digestion, which can cause bloating and discomfort during exercise. Fast-digesting forms like whey hydrolysate or amino acid supplements are more suitable.

For fasted training, an intra-workout supplement of BCAAs or EAAs can be particularly helpful. This provides amino acids to prevent muscle protein breakdown (catabolism) without a significant caloric load or disrupting a fast, though it may be a minor boost compared to adequate daily intake.

Evidence is mixed. While some older studies on 'time to exhaustion' showed benefits, more recent studies using 'time trial' performance measures found no acute performance-enhancing effects of adding protein to a carbohydrate drink for exercise performance beyond what ample carbohydrates already provide. However, it may improve training efficiency over time by supporting recovery.

Yes, especially for longer workouts. Carbohydrates are the primary fuel source for intense exercise. Combining carbs with protein helps replenish glycogen stores, provides sustained energy, and synergistically supports muscle recovery and protein synthesis.