Learn how endurance athletes use continuous glucose monitoring to optimise carb loading for peak performance before competitions.

Keywords: carb loading, continuous glucose monitor, endurance athletes, glycogen storage, performance optimisation

Carb loading with a CGM (Continuous Glucose Monitor) helps endurance athletes optimise glycogen storage for better performance. Here's what you need to know:

What is Carb Loading? A strategy to increase glycogen stores by eating 10-12g of carbs per kg of body weight daily for 36-48 hours before an event.

How CGM Helps: Tracks glucose in real time to avoid overloading, time carb intake, and ensure glycogen levels are optimised.

Key Tools: Devices like Dexcom G6, Freestyle Libre, or programs like Vively provide real-time data and personalised feedback.

Practical Tips: Use CGM to monitor glucose during workouts (aim for 5.6–7.8 mmol/L), adjust carb portions, and recover effectively post-exercise.

Using CGM, athletes can fine-tune their carb-loading process for peak performance.

The Science Behind Carb Loading

How Carbs Fuel Performance

Carbohydrates serve as the main energy source for endurance activities, stored in the muscles and liver as glycogen. During long periods of exercise, glycogen becomes the key energy supply needed to maintain performance.

To maximise glycogen stores, endurance athletes are advised to consume 10–12 grams of carbohydrates per kilogram of body weight daily for 36–48 hours before their event. Using Continuous Glucose Monitoring (CGM) tools, athletes can assess how well their carb-loading efforts are translating into glycogen storage, helping them fine-tune their energy reserves for optimal performance.

A deeper understanding of how the body manages glucose during exercise can make these strategies even more effective.

How Glucose is Regulated During Exercise

The body uses a precise hormonal system to keep glucose levels in balance during exercise. Two key hormones play a central role:

Insulin ensures glucose is absorbed into cells, while glucagon releases stored glycogen to maintain energy levels. With a CGM, athletes can track these glucose changes in real time, helping them stay within the ideal range for performance.

For the best results, athletes should aim to keep glucose levels below 7.8 mmol/L during activity and ensure levels return to baseline within two hours of consuming carbohydrates [3]. A CGM allows for real-time monitoring of these fluctuations, ensuring energy levels are where they need to be for peak performance.

Using CGM to Improve Carb Loading

Understanding glycaemic patterns, including the glycaemic index of different foods, is key for athletes aiming to optimise carb loading. Continuous Glucose Monitoring (CGM) devices can help keep glucose levels within target ranges while building glycogen stores.

Staying hydrated is crucial, as dehydration can skew glucose readings and disrupt your carb-loading plan. These insights allow athletes to create a more personalised strategy based on their unique glucose responses.

Creating a Carb Loading Plan with CGM

A properly designed carb-loading plan ensures glycogen stores are maximised while keeping glucose levels stable for top performance. Experts suggest consuming 10–12 grams of carbohydrates per kilogram of body weight daily during the 36–48 hours leading up to competition.

To refine your approach:

• Track your baseline glucose levels and experiment with different carb sources during training.
• Use CGM data to spot trends in glucose responses.
• Pair carbohydrates with protein to help control glucose spikes and aid glycogen storage.

Programs like Vively's CGM offer real-time feedback, helping athletes fine-tune their nutrition timing and portion sizes based on individual glucose responses. This data-driven approach can make carb loading more effective and personalised.

Practical Tips for Using CGM in Carb Loading

Carb Loading Before a Workout

If you're looking to maximise glycogen stores before a workout, carb loading is the way to go. A Continuous Glucose Monitor (CGM) can help you figure out the best timing and amount of carbs for your body. By tracking your glucose response, you can fine-tune your fuelling strategy.

Once you've nailed your pre-workout carbs, you can use CGM to keep your glucose levels steady while you exercise.

Managing Glucose During a Workout

Real-time CGM readings are a game-changer for keeping energy levels stable during your workout. If your glucose levels start to drop suddenly, it might be time for some mid-workout carbs.

For endurance sessions lasting over 90 minutes:

• Keep an eye on your CGM every 15-30 minutes.
• Aim to maintain glucose levels between 5.6–7.8 mmol/L.
• Adjust your carb intake based on how hard you're pushing yourself.

With stable glucose levels during your workout, you'll be set up for effective recovery afterward.

Refueling After a Workout

Post-workout recovery is all about replenishing glycogen stores, and CGM data can help you fine-tune your approach. By tracking how quickly your glucose returns to baseline, you can tweak your timing and portions for better results.

Here’s a simple plan: consume fast-acting carbs (0.5g/kg) within 30 minutes of finishing your workout. Use your CGM to check that glucose levels are back to baseline within two hours, and adjust as needed based on your body's response.

If you’re using Vively’s CGM program, you’ll get real-time feedback on how your post-workout nutrition is working. This lets you customise your recovery plan based on actual data, not just general advice.

Tools and Resources for Using CGM

Vively's CGM Program

Vively offers a CGM program designed specifically for athletes and fitness enthusiasts looking to fine-tune their carb-loading strategies. This program combines continuous glucose monitoring with personalised nutrition coaching, giving users real-time insights and integration with wearables. Through its mobile app, users receive instant feedback on how their glucose levels respond to different foods and exercises, allowing them to make precise adjustments to their carb-loading approach.

While Vively provides a specialised solution, there are other CGM devices and apps that can also assist in optimising carb-loading practices.

Other CGM Devices and Apps

Here are some well-known CGM devices that can help athletes manage their glucose levels effectively:

These devices are particularly useful for keeping glucose levels within the 100-140 mg/dL range during endurance activities. To get the most out of these tools, athletes can explore various educational resources that explain how to interpret CGM data for better carb-loading results.

Learning Resources for CGM Users

For athletes looking to deepen their understanding of CGM and carb loading, there are several educational resources available:

• The Gatorade Sports Science Institute provides research and guides focused on using CGM data to tailor carbohydrate intake. Their materials help athletes maximise glycogen storage and maintain steady blood glucose levels.
• The Levels platform offers articles and case studies that dive into CGM use in sports performance. These resources help athletes analyse their unique glucose patterns and refine their carb-loading strategies.

Additional resources to consider include:

• Peer-reviewed studies published in sports nutrition journals
• Workshops on glucose management and sports nutrition strategies

These tools and resources can empower athletes to use CGM data effectively, enhancing their performance through smarter carb-loading techniques.

Conclusion: Using CGM to Improve Carb Loading

Continuous glucose monitoring (CGM) has changed the way athletes approach carbohydrate loading. By providing real-time data, CGM devices help athletes make precise adjustments to maximise glycogen storage while avoiding mistakes that could hurt performance.

With CGM, athletes can turn carb loading into a science-backed, data-driven strategy. Athletes can adjust their carbohydrate intake to consume 10-12 grams of carbs per kilogram of body weight each day during the 36-48 hours before a competition. This helps them store energy for better performance. By tracking glucose levels and identifying sustained elevations during this phase, CGM helps ensure glycogen stores are filled efficiently and tailored to the athlete's unique needs.

Platforms like Vively combine CGM data with personalised coaching, helping athletes refine their carb-loading process even further. This technology has shifted carb loading from a one-size-fits-all approach to one that aligns with individual physiological responses.

To perform at their best, athletes should aim to keep glucose levels between 5.6 and 7.8 mmol/L during endurance activities, avoiding spikes greater than 1.7 mmol/L. With CGM, athletes can take control of their nutrition and performance, pushing their limits in endurance sports.