Intraworkout Carbohydrate Supplementation

If you’ve been training seriously for any length of time, you’ve probably heard about fueling your body before and after a workout. But what about during your workout? That’s where intraworkout carbohydrate supplementation comes into play.

Intraworkout carbohydrate supplementation is a potential strategy for maximising performance, sustaining energy, and improving recovery, especially if you’re training intensely, for long durations, or engaging in endurance-based activities.

Having worked with athletes, bodybuilders, and everyday fitness enthusiasts, I want to break down everything you need to know about intraworkout carbohydrate supplementation, so you can make the best decisions possible. Whether you’re looking to push through plateaus, prevent fatigue, or optimise your gains, this article will ensure you make the most of your nutrition during training sessions.

Why Carbohydrates Matter During Exercise

Carbohydrates are your body’s primary fuel source during exercise, especially when engaging in high-intensity training. Unlike fats and proteins, which require more time and oxygen to convert into usable energy, carbohydrates provide a rapid and efficient source of energy in the form of glucose. This quick accessibility makes them indispensable for sustaining peak performance, delaying fatigue, and optimizing recovery.

The Science Behind Intraworkout Carbohydrate Supplementation

During exercise, your muscles rely on two main carbohydrate sources: muscle glycogen (stored carbohydrates) and blood glucose. These energy reserves fuel muscle contractions, help maintain endurance, and support high-intensity efforts. However, glycogen stores are finite.

If they become depleted too quickly, your body shifts toward less efficient fuel sources (fat and protein) leading to fatigue, decreased power output, and impaired performance.

Understanding Glycogen Depletion

Relative glycogen depletion occurs when available carbohydrate stores in muscle tissues run low, and its impact varies based on training intensity:

• Low-intensity exercise (walking, yoga): Minimal glycogen depletion, as fat remains the primary fuel source.
• Moderate-intensity exercise (jogging, weightlifting): Glycogen is gradually utilised, requiring a moderate replenishment strategy.
• High-intensity exercise (sprinting, HIIT, CrossFit): Glycogen stores can be relatively depleted within 60-90 minutes, leading to a decline in performance and increased perceived exertion.

If activities go on for a long enough time, glycogen levels will slowly deplete, even if intensity levels aren’t that high.

Once glycogen levels drop significantly, high intensity energy output diminishes, endurance suffers, and athletes may experience “hitting the wall”, a sudden and extreme energy crash. This is where intraworkout carbohydrate supplementation plays a role.

Glycogen and Glucose Absorption and Utilisation Explained

Your body absorbs glucose through the small intestine and transports it into the bloodstream. From there, insulin signals cells to absorb glucose and either convert it into glycogen (for later use) or immediately utilise it for energy production.

The absorption of glucose is a well-orchestrated process:

• Carbohydrates are broken down into glucose in the digestive tract.
• Glucose enters the bloodstream and is transported to cells.
• Insulin facilitates glucose uptake, directing it to muscles for immediate energy use or storing it as glycogen for later.

If glucose levels drop too low, the body turns to fat and protein metabolism, which leads to:

• Slower ATP production: Lower energy output and sluggish performance.
• Increased muscle breakdown: Protein is converted to glucose, leading to muscle loss over time.
• Higher perceived exertion: Workouts feel harder and less effective due to limited energy availability.

If the body needs it now, the glucose will be used to fuel the activity, rather than being stored for later. If this happens, protein and fat utilisation (i.e. conversion to energy) are halted.

Benefits of Intraworkout Carbohydrate Supplementation

This is where intraworkout carbohydrate supplementation comes in. Consuming carbohydrates during exercise offers several performance-enhancing benefits:

• Maintains blood glucose levels: Prevents sharp energy drops, keeping performance stable.
• Sustains energy output: Provides a steady stream of fuel for prolonged activity.
• Delays muscle fatigue: Allows for longer and more intense training sessions.
• Prevents muscle breakdown: Preserves lean muscle mass by sparing protein from being used as fuel.
• Enhances post-exercise recovery: Accelerates glycogen replenishment, reducing soreness and improving training consistency
• Maintains cognitive function: Due to the steady supply of glucose, cognitive function stays higher while working out, which is essential for sports requiring mental focus and coordination.
• Reduces recovery time: Helps athletes adapt faster to high training volumes.

By optimising carbohydrate intake during exercise, athletes can maximise performance, minimise fatigue, and accelerate recovery. Understanding your body’s energy needs and adjusting your carb strategy accordingly will ensure you’re always training and competing at your best.

Who Needs Intraworkout Carbohydrate Supplementation?

Not everyone needs to consume carbs during their workout. The necessity depends on training duration, intensity, and goals. It also depends on how the rest of the diet is set up. So before thinking that you absolutely need intraworkout carbohydrate supplementation, you need to make sure the rest of your diet is set up correctly.

I recommend reading the following articles before you even consider intraworkout carbohydrate supplementation:

• How Many Calories Should You Eat?
• How Much Protein Should You Eat?
• How Much Fat Should You Eat?
• How Much Carbohydrate Should You Eat?

Assuming your diet is relatively well set up, we can then start looking into whether intraworkout carb supplementation makes sense.

You Should Consider Intraworkout Carbs If:

• You do not eat carbohydrates before your training session.
• Your workout lasts longer than 60 minutes, especially if it’s high-intensity or endurance-based.
• You engage in high-intensity interval training (HIIT), Hyrox, CrossFit, or resistance training with high volume and short rest periods.
• You train twice a day or have multiple sessions in a short timeframe, meaning glycogen stores may not fully replenish between workouts.
• You’re in a muscle-gaining phase and need to sustain high training intensity and volume without early fatigue.
• You’re in a caloric surplus and want to ensure optimal energy availability for performance and muscle growth.
• You’re an endurance athlete (cyclist, runner, swimmer) needing sustained glucose availability for prolonged sessions.
• You sweat heavily and need to replenish energy quickly alongside electrolytes to avoid dehydration and fatigue.
• You experience mid-workout energy crashes and need a steady fuel source to maintain consistent performance.
• You participate in competitive sports or tournaments that require peak performance over extended periods.

You May Not Need Them If:

• You already eat a decent portion of carbohydrates before your workout.
• Your session is under 45 minutes and consists of lower-intensity activities like light weight training, walking, or yoga.
• You’re primarily engaging in low-intensity, lower-volume resistance training where glycogen depletion is minimal and energy demands are lower.
• You’re in a fat loss phase and strategically limiting carbohydrate intake to prioritise fat metabolism (only really applicable to individuals who are already very lean and are trying to get every little bit of fat off their body).
• You have a low total daily calorie intake, and consuming carbs during a workout would interfere with maintaining an overall caloric deficit.
• Your training style focuses on aerobic base-building at lower intensities where fat metabolism is the dominant energy system, and your overall volume isn’t excessively high.
• You prefer to obtain all your carbohydrates pre- and post-workout, avoiding intraworkout nutrition for simplicity.

In summary, intraworkout carbohydrate supplementation is highly beneficial for those training at high intensities, high volumes, for long durations, or in multiple daily sessions. However, it may be unnecessary for individuals with shorter, lower-intensity, lower-volume workouts, those prioritising fat oxidation, or those on low calories. Understanding your training style, energy demands, and nutritional goals will determine whether intraworkout carbs are a good fit for you.

Choosing the Right Carbohydrates

Not all carbs are created equal when it comes to intraworkout fueling. You want fast-digesting carbohydrates that are easily absorbed and won’t cause digestive distress.

Best Intraworkout Carbs

Ultimately, you just want to choose a carb source that is absorbed quickly and doesn’t cause you any digestive issues. Beyond this, you may want to avoid the following:

• Fibre-rich carbs (oats, whole grains) as these slow digestion, and may cause bloating.
• Excessive fats & proteins, as these slow down digestion and delay energy availability.
• High-fructose sources alone, as this can cause digestive distress if consumed in excess.

How Much Should You Take?

The amount of intraworkout carbohydrates depends on multiple factors, including the intensity, duration, and type of training, individual tolerance levels, and overall dietary goals. Proper dosage ensures sustained energy, optimal performance, and improved recovery.

General Intraworkout Carbohydrate Intake Recommendations Based on Workout Duration and Intensity

• Less than 60 minutes, low-moderate intensity: No carbohydrates needed, as muscle glycogen stores should be sufficient.
• 60-90 minutes, high-intensity training: 20-40g of carbohydrates to maintain energy output and avoid early fatigue.
• 90+ minutes, endurance training: 30-60g of carbohydrates per hour to sustain glycogen stores and improve prolonged performance.
• Ultra-endurance events (3+ hours): 30-90g of carbohydrates per hour, using a combination of glucose and fructose for better absorption and oxidation rates.

For purely strength athletes, 20-30g of a fast-digesting carbohydrate source can help sustain performance, reduce muscle breakdown, and enhance recovery during long resistance training sessions.

Factors That Influence Your Carb Intake Needs

Ultimately, I always believe that to truly master your own diet, you have to understand the rationale behind the general recommendations. This then allows you to tailor things to your specific needs. As such, I want you to keep the following things in mind:

1. Training Intensity: Higher intensity workouts deplete glycogen faster, requiring greater carbohydrate replenishment.
2. Training Duration: The longer the workout, generally, the greater the carbohydrate demand.
3. Bodyweight and Muscle Mass: Larger individuals with more muscle likely require higher carbohydrate intake for fuel.
4. Metabolic Rate: Some athletes burn through glycogen stores faster and may need more frequent carbohydrate intake.
5. Training Environment: High temperatures and humid conditions increase energy expenditure and the need for additional fueling.
6. Dietary Context: If you train in a glycogen-depleted state (e.g., fasted training or ketogenic diets), you may require more carbohydrates to sustain energy levels.

Carb Intake for Different Athletes

Carbohydrate needs vary depending on the type of activity and energy demands, and understanding these will also help you to refine your intake to your needs.

Endurance Athletes (runners, cyclists, swimmers)

• Heavy reliance on glycogen for sustained efforts.
• Carbohydrate intake helps maintain stamina and prevents “bonking.”
• Recommended intake: 30-60g of carbohydrates per hour of endurance exercise.

Strength Athletes (powerlifters, bodybuilders, Olympic lifters)

• Glycogen is crucial for explosive movements and maximal effort lifts.
• Carbs help sustain ATP production for repeated bouts of heavy lifting.
• Recommended intake: 20-30g of fast-digesting carbs per session.

High-Intensity Sports (football, soccer, CrossFit, martial arts)

• Quick bursts of energy require rapid glycogen replenishment.
• Carbs aid in recovery between rounds, plays, or matches.
• Recommended intake: 30-50g of carbohydrates per session, depending on duration and intensity.

When to Take Intraworkout Carbs

Timing is crucial for maximising performance benefits. The most effective approach is to consume carbohydrates consistently throughout your session rather than all at once. This ensures a steady energy supply while preventing digestive discomfort.

Timing Guidelines for Intraworkout Carbohydrates

• Begin consuming carbs 20-30 minutes into your workout to ensure a steady glucose supply when glycogen begins depleting.
• Continue sipping carbohydrates every 15-20 minutes to maintain stable blood glucose levels and prevent energy crashes.
• Pair carbohydrate intake with adequate hydration and electrolytes to optimize absorption and prevent dehydration.
• For longer endurance events, increase carbohydrate intake gradually to avoid stomach discomfort and maximize glycogen replenishment.

Should You Add Protein?

Combining protein with intraworkout carbs can be highly beneficial, especially for prolonged training sessions, strength athletes, and endurance competitors. Protein helps mitigate muscle breakdown, speeds up recovery, and enhances endurance when consumed alongside carbohydrates.

Carb-to-Protein Ratio for Optimal Performance

• 2:1 (Carbs:Protein) is an effective starting point for most athletes.
• Example: 20-30g carbohydrates combined with 10-15g essential amino acids (EAAs) or hydrolysed whey protein.
• Why? This combination reduces protein catabolism, supports muscle repair, and maintains endurance levels.
• For endurance athletes, a 3:1 ratio (Carbs:Protein) may be ideal to replenish glycogen stores while reducing muscle protein breakdown over extended periods.

Hydration and Electrolytes: The Missing Piece

Hydration and electrolyte balance also play an essential role in maintaining peak performance. Dehydration, even at low levels, can impair endurance, strength, and cognitive function, making fluid and electrolyte intake crucial.

Essential Electrolytes for Performance

• Sodium (Na): Helps retain water, maintain blood pressure, and support nerve function.
• Potassium (K): Prevents muscle cramps and aids in proper muscle contractions.
• Magnesium (Mg): Supports energy metabolism, enzyme function, and reduces muscle fatigue.
• Calcium (Ca): Plays a key role in muscle contraction and neurotransmission.

Best Practices for Hydration and Electrolytes

• Combine your intraworkout carbohydrate drink with water and electrolytes to ensure proper absorption and hydration.
• Consume 500-1000mg of sodium per hour for endurance events, particularly in hot conditions.
• Use natural sources like coconut water or formulated electrolyte powders if you sweat excessively during training.
• Avoid overhydration, which can dilute sodium levels and lead to hyponatremia (low blood sodium). Balance is key.

Common Mistakes and How to Avoid Them

1. Taking Too Many Carbs Too Quickly: Consuming large amounts of carbohydrates in one go can cause bloating and stomach discomfort. Sip gradually instead.
2. Using the Wrong Carb Source: Stick to easily digestible carbs like dextrose, maltodextrin, or highly branched cyclic dextrin (HBCD) to prevent GI distress.
3. Ignoring Electrolytes: Dehydration and imbalanced electrolytes can significantly impact performance, so ensure adequate intake.
4. Not Testing Your Strategy: Experiment with carbohydrate intake during training rather than waiting for competition or race day.
5. Neglecting Overall Nutrition: Intraworkout carbs complement, but do not replace, a well-structured nutrition plan.

To get the most out of your carbohydrate use during training, consider these key strategies:

• Gradual Carb Integration: Start with small amounts of intraworkout carbs and increase intake based on tolerance, and results.
• Timing Strategies: Distribute carb intake evenly throughout the workout for sustained energy. Don’t make the mistake of just front loading all your carbohydrates
• Personalised Approaches: Experiment with different carb sources (e.g., dextrose, maltodextrin, cyclic dextrin) to find what works best for you.

Final Thoughts on Intraworkout Carbohydrate Supplementation

Intraworkout carbohydrate supplementation is a powerful tool for optimising athletic performance, sustaining energy, and accelerating recovery. By carefully selecting the right carbohydrate sources, monitoring intake timing, and balancing hydration, athletes can train harder, longer, and with greater efficiency.

Key Takeaways:

• Tailor your carbohydrate intake to your training duration, intensity, and individual energy needs.
• Combine carbs with protein for muscle preservation and enhanced endurance.
• Pair carbohydrate intake with adequate hydration and electrolyte replenishment to maintain peak performance.
• Test and refine your fueling strategy in training sessions to find the optimal approach for your body.

The key is understanding your body’s needs and fine-tuning your fueling strategy for maximum performance benefits.

If you are really struggling to set up your diet effectively, and can’t figure out your intra-workout nutrition, then it may make sense to look into online coaching. It isn’t for everyone, but if you need specific help, then obviously getting professional help is going to solve your issues in the most time efficient manner.

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