The Science Behind Running Fuel: Carbohydrates are Key
For endurance athletes, carbohydrates are the body's primary fuel source, stored as glycogen in the muscles and liver. During prolonged exercise, these glycogen stores are gradually depleted, leading to the familiar feeling of 'hitting the wall'. To counteract this and sustain performance, it is necessary to replenish carbohydrates mid-run. Energy gels and chews are highly concentrated sources of simple carbohydrates, designed for quick and efficient digestion. Both products deliver the essential fuel needed, but their physical form creates important differences in how the body processes them, and how they feel to consume on the go. Understanding these distinctions is crucial for optimizing your nutrition strategy.
Energy Gels: Quick Fuel for High Intensity
Energy gels are a concentrated, syrupy liquid containing simple sugars like glucose and fructose. They are packaged in small, easy-to-carry sachets designed for rapid consumption. The key benefit of a gel is its speed. Because it is already in a semi-liquid state, the body can absorb and convert its carbohydrates into energy very quickly, providing a fast and immediate boost. This makes gels particularly advantageous during high-intensity efforts, such as the final push in a race or tackling a steep incline, where chewing and swallowing are more difficult due to heavy breathing.
Types and Considerations for Gels
- Classic Gels: Require water to aid digestion and absorption. Without water, the high sugar concentration can pull fluid into the stomach, potentially causing bloating or cramps.
- Isotonic Gels: Thinner in consistency with added water and electrolytes, allowing for consumption without additional fluid. This is convenient but means a larger package to carry.
- Caffeinated Gels: Include caffeine for an extra mental and physical boost, useful for late-stage races, but should be tested in training for tolerance.
- Flavor Fatigue: Some runners find the sweet, syrupy texture and taste of gels unpleasant over long periods.
Energy Chews: Sustained Energy for Longer Efforts
Energy chews, often called gummies or blocks, are solid, carbohydrate-dense snacks that resemble candy. They offer a more gradual energy release compared to gels, making them well-suited for steady, long-distance efforts at lower intensity. For many, the act of chewing provides a more satisfying and familiar feeling than the quick swallow of a gel, which can combat flavor fatigue.
Portion Control and Practicality for Chews
- Controlled Consumption: Chews are typically multi-serving, allowing runners to consume a few pieces at a time and save the rest for later. This provides greater control over carbohydrate intake throughout the run.
- Less Messy: Unlike gels, chews are solid and less likely to cause a sticky mess if not fully consumed in one go.
- Digestive Comfort: Many athletes with sensitive stomachs find chews easier to digest, as they mimic the slower intake of whole foods.
- The Chewing Challenge: When running at high speeds or breathing heavily, the physical act of chewing can be difficult and disruptive.
The Great Comparison: Gels vs. Chews
Your choice between chews and gels ultimately depends on several factors, including the intensity of your run, personal preference, and digestive tolerance. The following table summarizes the key differences:
| Feature | Energy Gels | Energy Chews |
|---|---|---|
| Form | Liquid, syrupy | Solid, gummy-like |
| Energy Release | Rapid, immediate boost | Gradual, more sustained |
| Best For | High-intensity efforts, short-to-moderate runs | Longer, sustained efforts, lower intensity runs |
| Consumption | Squeeze and swallow quickly | Chewed and swallowed |
| Digestion | Fast absorption, can cause stomach upset | Slower digestion, potentially easier on sensitive stomachs |
| Fluid Needs | Typically require water, unless isotonic | Requires fluid for digestion and absorption |
| Portioning | Single-serving packets | Can be portioned easily throughout the run |
| Convenience | Fast, no chewing required | Less messy, but requires chewing |
| Considerations | Potential for "flavor fatigue" or messy packaging | Chewing can be difficult when breathing heavily |
Finding Your Optimal Fueling Strategy
There is no single correct answer for every runner; finding what works best is a process of testing and adaptation. For most runners, a fueling strategy is not an either/or situation but a combination of both products depending on the scenario. For instance, a marathon runner might use chews during the slower, steady middle miles to maintain a consistent energy flow and reduce flavor fatigue, then switch to a gel for a quick burst of energy before a final sprint or a difficult section.
To develop your ideal approach, experiment with different brands and formats during training, not on race day. Pay close attention to how your body reacts, noting any digestive issues or energy fluctuations. Remember to always consume energy products with plenty of water to aid digestion and absorption, unless using an isotonic gel. The best fuel is the one that you can successfully consume and that keeps you feeling strong and energized throughout your run.
Conclusion: Personal Preference and Purpose Prevail
Choosing between chews and gels for running comes down to personal preference, the nature of your activity, and your body's unique response to different fuel formats. Gels offer a quick, easily consumed burst of energy, perfect for high-intensity moments. Chews provide a more satisfying and gradual release, ideal for longer, steady efforts and portion control. By experimenting during training and listening to your body, you can confidently integrate the right fuel into your nutrition plan to maximize your performance and enjoyment on the run.
For more in-depth nutritional guidance, consider consulting with a sports dietitian.
The Final Verdict
While gels are excellent for rapid energy delivery during intense phases, chews are often better for steady, long-distance runs and sensitive stomachs. The most effective approach is often a combination of both, strategically deployed based on your run's demands.
A Balanced Approach
Many runners combine gels and chews. For example, using chews for steady fueling during long training runs and saving a caffeinated gel for the final push on race day.
Testing During Training
Before a big race, it is essential to practice your fueling strategy during training sessions that mimic race-day conditions. This helps your digestive system adapt and prevents unexpected issues.
High-Intensity vs. Long-Distance
For short, high-intensity runs (under 90 minutes), pre-run fueling and a potential mid-run gel may suffice. For marathons and ultras, chews are often a better choice for consistent, sustained energy release.
Hydration is Non-Negotiable
Regardless of your fuel choice, consuming adequate water or an electrolyte drink is critical. Water helps your body process the carbohydrates and is essential for preventing dehydration and stomach upset.
Listen to Your Body
Digestive tolerance is highly individual. Some runners find gels easier on the stomach, while others prefer the solid form of chews. Never try a new fueling product or strategy on race day.
