The Science of Glycogen and Why Timing is Everything
When you engage in prolonged, high-intensity exercise, your body primarily relies on stored carbohydrates, known as glycogen, for fuel. For most endurance athletes, these glycogen reserves last for approximately 90 minutes. Once depleted, the body is forced to rely on slower-burning fat stores, leading to a noticeable drop in energy, a phenomenon known as 'hitting the wall' or 'bonking'. Strategic consumption of carb gels is designed to counteract this energy crash by providing a rapid influx of simple sugars that are quickly absorbed into the bloodstream.
Your Pre-Race and Pre-Workout Fueling Strategy
Properly fueling your body before an event or long training session can give you a crucial head start. A carb gel can be a convenient part of this strategy, especially if you haven't had a full meal in several hours.
15–30 Minutes Before Exercise: Consuming a gel in this timeframe allows the carbohydrates to enter your system as you begin your activity, ensuring a readily available energy source from the outset. This is particularly beneficial for longer events or intense workouts where you need to perform at your peak from the start. Taking a gel too early, however, can cause a blood sugar spike and crash, especially for shorter distances, so timing is key.
For Shorter, High-Intensity Efforts: For events or workouts lasting under 60-75 minutes, a carb gel is often unnecessary if you are well-fueled beforehand. Your existing glycogen stores should be sufficient. The exception is if you are training fasted, in which case a gel beforehand can help boost performance without a heavy feeling.
In-Activity Fueling for Endurance
This is where carb gels earn their stripes. Consistent, regular intake is the key to maintaining a steady supply of energy and preventing the dreaded energy crash. The general rule is to start fueling after the first hour of exercise and continue at regular intervals.
- Start Early: For any activity lasting over 75-90 minutes, start taking gels approximately 60 minutes into the workout. You should not wait until you feel fatigued.
- Maintain Regular Intervals: Follow up with another gel every 30-45 minutes thereafter. Some gels are more concentrated, so refer to the brand's specific guidance.
- Hydrate with Water: Most traditional gels are hypertonic, meaning they require water to be properly absorbed by the body without causing gastrointestinal distress. Always take gels with a few sips of water to facilitate digestion and absorption. Isotonic gels, which already contain water, are the exception.
A Comparison of Carb Gel Types
| Gel Type | Characteristics | Best For | Considerations |
|---|---|---|---|
| Classic Gels | Concentrated, thick consistency. Requires water for absorption. | Experienced athletes who have tested the formula and want a compact energy source. | High risk of stomach upset if not taken with enough water. |
| Isotonic Gels | Thinner, more watery consistency. Can be taken without additional water. | Runners or hot weather conditions where carrying extra water for every gel is inconvenient. | Bulkier packaging due to the added water content. |
| Caffeinated Gels | Contain added caffeine for a mental and performance boost. | Later stages of a long race or when a mental lift is needed. | Test in training first to assess tolerance; can cause jitters in sensitive individuals. |
| Electrolyte Gels | Include essential minerals like sodium to help replace sweat losses. | Long, hot workouts or events where significant sweating occurs and cramping is a concern. | Still requires hydration, either from water or isotonic formula. |
| Natural Gels | Made from real food ingredients like fruit purees and chia seeds. | Athletes with sensitive stomachs or those who prefer natural ingredients. | Consistency and absorption rates can vary by flavor; may be lower in total carbs. |
Practical Tips for Using Carb Gels Effectively
- Train Your Gut: Never try a new gel or fuelling strategy on race day. Your digestive system needs to be trained to process concentrated carbohydrates during intense physical activity. Practice with your chosen gels during your long training sessions to find what works best for you.
- Consider Your Needs: The amount of carbohydrates you need per hour depends on the duration and intensity of your exercise. Athletes in ultra-endurance events may need up to 90g of carbs per hour, while those in shorter marathons may aim for 30-60g. The dual-carb formulas (glucose and fructose) are designed to help your body absorb more carbohydrates per hour.
- Combine and Conquer: You don't have to rely solely on gels. Many endurance athletes use a combination of carb gels, sports drinks, and whole foods to meet their fuelling needs. Using gels for a quick boost while sipping a carbohydrate-electrolyte drink can be an effective strategy.
The Recovery Role of Carb Gels
While most athletes associate carb gels with performance, they can also assist in post-exercise recovery. Consuming a carb gel within 30 minutes after an intense workout can kickstart the glycogen replenishment process. Pairing it with a source of protein will help repair muscle tissue, providing a complete recovery solution. This is a quick and convenient option when a full meal is not immediately available.
Conclusion: Fuel Smart, Perform Stronger
Knowing when should you take carb gels is not a one-size-fits-all formula, but rather a strategic approach based on your activity, intensity, and personal tolerance. For endurance events exceeding 90 minutes, consistent mid-race fuelling is essential to prevent glycogen depletion. By training with different types of gels, timing your intake effectively, and ensuring proper hydration, you can maximize your energy levels and sustain peak performance. Ultimately, the best strategy is a well-practiced one, allowing you to focus on your race with confidence in your fuelling plan. For more detailed nutrition guidance, consult a sports nutritionist or a certified coach who can help fine-tune your approach for your specific needs.
The Critical Timing for Carb Gel Use
- Pre-Event: 15-30 minutes before starting any high-intensity or long-duration activity to top off glycogen stores.
- Mid-Endurance: Begin consuming after 60-90 minutes of continuous exercise, then every 30-45 minutes to prevent depletion.
- Listen to Your Body: Take a gel sooner if you feel an energy dip, sluggishness, or a struggle to maintain pace.
- Hydrate Consistently: Always consume traditional gels with water to ensure proper absorption and avoid stomach issues.
- Post-Workout: Use a carb gel in the 30-minute recovery window after an intense session to rapidly replenish glycogen.
- Train with Gels: Practice your fuelling strategy during long training sessions, not for the first time on race day.
Frequently Asked Questions
1. How long do carb gels take to work? Carb gels typically start working within 5 to 15 minutes of consumption, as the simple sugars are quickly absorbed into the bloodstream. Absorption rates can vary based on the type of gel and individual metabolism.
2. Do I need to drink water with carb gels? Yes, for traditional (hypertonic) carb gels, you must drink water to aid absorption and prevent gastrointestinal discomfort. Isotonic gels are the exception and are formulated to be taken without extra water.
3. Are carb gels necessary for short runs, like a 5k or 10k? For most people, carb gels are not necessary for runs under an hour, as your body's stored glycogen is sufficient. The exception is if you are running fasted or at a very high intensity.
4. Can I use carb gels for any sport? Carb gels are designed for endurance athletes across various sports, including running, cycling, swimming, and triathlon. Their portability and fast-acting energy make them ideal for on-the-go fueling.
5. Can carb gels cause stomach issues? Some athletes experience gastrointestinal distress with carb gels, often from overconsumption or not taking them with enough water. Training with gels is crucial to determine your body's tolerance.
6. What is the difference between classic and isotonic gels? Classic gels are thick and concentrated, requiring water to be digested properly. Isotonic gels are pre-mixed with water, have a thinner consistency, and can be consumed without additional fluid, making them less likely to cause stomach upset.
7. What is the benefit of a carb gel with a mix of glucose and fructose? A combination of glucose and fructose utilizes different transport channels in the gut, allowing the body to absorb more carbohydrates per hour and potentially reducing the risk of gastric issues. This is particularly beneficial for high-intensity, long-duration efforts.
