Energy gels are a staple for endurance athletes, offering a concentrated, fast-acting source of carbohydrates to replenish depleted glycogen stores. However, improper use, particularly concerning hydration, can lead to performance-ruining side effects. The simple act of drinking water after consuming an energy gel is a critical component of effective fueling and optimal performance. This article explains the physiological processes involved and outlines best practices for runners and other endurance athletes.
The Crucial Role of Water in Digestion
When you consume a standard (hypertonic) energy gel, you are ingesting a solution with a high concentration of sugar. For your body to absorb these carbohydrates quickly and efficiently, it must dilute this mixture to a concentration that is closer to that of your blood plasma. To accomplish this, water is drawn from your body's cells and bloodstream into the gut. This process is known as osmosis. Drinking water alongside your gel provides the necessary fluid directly, assisting the digestive system rather than forcing it to pull precious fluids from elsewhere in your body.
What happens without sufficient water?
Without adequate water, the gut struggles to process the highly concentrated gel, leading to several negative outcomes:
- Dehydration: Pulling fluid from the bloodstream to dilute the gel exacerbates dehydration, which is already a risk during prolonged exercise due to sweating. This can negatively impact performance and overall health.
- Gastrointestinal Distress: A sluggish digestive process can cause stomach upset, leading to cramping, bloating, nausea, and even diarrhea. This is often referred to as 'runner's trots'.
- Delayed Absorption: The concentrated gel sits in the stomach longer, delaying the delivery of carbohydrates to your working muscles and postponing the energy boost you need.
The Different Types of Gels and Hydration Needs
Not all energy gels are created equal, and your hydration strategy depends on the type you're using. Understanding the difference between traditional and isotonic gels is key to proper fuelling.
Traditional (Hypertonic) Gels
These gels are highly concentrated and require you to drink water immediately after consuming them. They deliver a large carbohydrate load in a small package, making them an efficient source of fuel, especially for cyclists who carry water bottles.
Isotonic Gels
Isotonic gels are pre-mixed with fluid to a concentration similar to the body's fluids, allowing them to be absorbed more quickly and without the immediate need for extra water. While convenient, especially for runners who might not carry a bottle, they contain fewer carbohydrates per serving than traditional gels. It is important to note that consuming an isotonic gel does not replace your overall hydration needs, and you should still drink water throughout your activity.
| Feature | Traditional (Hypertonic) Gels | Isotonic Gels |
|---|---|---|
| Concentration | High sugar and carbohydrate density | Lower concentration, similar to body fluids |
| Water Requirement | Essential to drink water alongside | Can be consumed without extra water |
| Speed of Absorption | Dependent on water intake; potentially slower without it | Faster absorption due to pre-dilution |
| Carb Content | Higher carbohydrate load per sachet | Lower carbohydrate load per sachet |
| Primary Use | Efficient fuel source for prolonged activity | Rapid fuel and hydration in one, convenient for runners |
| GI Distress Risk | Higher if not combined with sufficient water | Lower risk of stomach upset |
How to Effectively Combine Gels and Water
The standard recommendation for traditional gels is to consume them with at least 4-6 ounces (120-180 ml) of plain water. This helps your body process the carbohydrates and minimizes the risk of stomach issues. For a long-distance race, it is advisable to time your gel consumption with aid stations to ensure you have water readily available. Remember to practice this strategy during your training runs to find what works best for your body.
When using isotonic gels, you don't need to gulp down water immediately, but you still need to stay hydrated. A general rule of thumb for endurance exercise is to aim for 16-32 ounces of fluid per hour, regardless of your gel type. Avoid combining a gel with a sports drink, as this can lead to an excessively high concentration of sugar, which increases the likelihood of gastric distress.
Conclusion
Drinking water after a traditional energy gel is not merely a recommendation—it is a physiological necessity for effective carbohydrate absorption and the prevention of dehydration and stomach upset. By providing the fluid needed to dilute the concentrated sugars, water ensures the energy is delivered quickly to your muscles. However, the rules change with isotonic gels, which are already diluted for faster absorption. No matter your choice, pairing your fueling with a consistent hydration plan is the ultimate recipe for sustained energy and a successful performance. Always test your nutrition strategy during training to avoid race-day surprises.
Find more expert advice on combining nutrition and hydration for endurance sports at Runners Need, where they explain the science behind energy gels and proper usage.
The bottom line: How to use energy gels correctly
- Prioritize Hydration: Always drink plain water immediately after consuming a standard energy gel to aid digestion and absorption.
- Know Your Gel Type: Understand the difference between traditional and isotonic gels to manage your water intake appropriately.
- Test in Training: Never try a new gel or fuelling strategy on race day. Practice during long training runs to train your gut.
- Listen to Your Body: Pay attention to how your body responds to different products and adjust your intake and water consumption accordingly.
- Stick to Plain Water: When consuming a gel, use plain water instead of a sports drink to avoid an overly concentrated sugar solution that can cause stomach issues.
