The Importance of Carbohydrates for Swimmers
Carbohydrates are the body's primary and most efficient energy source, especially during moderate to high-intensity exercise. For swimmers, this energy is stored in the muscles and liver as glycogen. During intense training or prolonged events, the body rapidly depletes these glycogen stores. Without proper fueling, this can lead to fatigue, reduced power, and a drop in overall performance—a feeling many athletes know as "hitting the wall". A consistent, strategic intake of carbohydrates helps maintain blood glucose levels, sparing your muscle glycogen and allowing you to train harder and longer.
How Many Carbs Per Hour of Swimming? The Breakdown
Determining your specific carbohydrate needs depends on several factors, including the duration and intensity of your swim. There is no one-size-fits-all number, but sports nutrition guidelines provide an excellent starting point.
General Guidelines for Prolonged Exercise
For exercise lasting 60 to 90 minutes, simple carbohydrates in the form of a sports drink are often sufficient to top off energy stores. For sessions extending beyond 90 minutes, active fueling is crucial. The recommended intake is typically 30-60 grams of simple carbohydrates per hour. This can be consumed through various products like gels, chews, or sports drinks, depending on personal preference and tolerance.
High-Intensity or Very Long Sessions
For swimmers undertaking very high-intensity training or marathon swimming events lasting over two hours, the body can tolerate and benefit from a higher intake of up to 90 grams of carbohydrates per hour. Reaching this higher intake can be optimized by using products with a specific glucose-to-fructose ratio (typically 2:1) to enhance absorption and reduce the risk of gastrointestinal discomfort. It's essential to practice this higher intake during training to ensure your body can handle it on race day.
Choosing the Right Fuel: Gels, Drinks, and Chews
For a swimmer, the practicalities of consuming fuel in the water can be challenging. Liquids and easily digestible gels or chews are generally preferred. Low-fiber, low-fat options are key to avoiding stomach distress during exercise.
Comparison of Mid-Swim Fueling Options
| Fuel Type | Pros | Cons | Carbs per Serving (Approx.) |
|---|---|---|---|
| Sports Gels | Quick, concentrated energy; easy to consume with minimal fluid; often available in different flavor and carb blends. | Can cause stomach upset if not practiced; sticky mess potential; flavor fatigue on longer swims. | 20-30g |
| Sports Drinks | Provides both hydration and carbohydrates simultaneously; often includes electrolytes to replace lost salts. | Bulky to carry; can lead to stomach sloshing if consumed too quickly; requires careful mixture for carb concentration. | 30-60g per liter |
| Energy Chews | Easy to carry and consume in small increments; provides a satisfying texture for some athletes. | Can require more chewing than gels or drinks; may need to be consumed with water. | 20-30g |
| Dried Fruit (Raisins, Dates) | Natural, easily digestible; provides a mix of simple sugars; familiar taste. | May be slower to digest than engineered products; can be difficult to handle with wet hands. | 15-25g per small handful |
Fueling Strategy for Different Swim Durations
No single strategy fits all training. Here’s a breakdown based on the length of your session:
- Short Sessions (Under 60 minutes): For sessions of this length, the focus should be on ensuring you start well-fueled and hydrated. A light, carbohydrate-focused snack 30-60 minutes prior is usually sufficient.
- Moderate Sessions (60-90 minutes): This is where intra-swim fueling can begin to offer benefits. Sips of a sports drink containing carbohydrates and electrolytes can help sustain energy levels, especially during high-intensity sets.
- Long Sessions (Over 90 minutes): Consistent fueling every 20-30 minutes is critical. A combination of a sports drink and gels or chews is an effective strategy. Aim for the 30-60g/hour target and practice your intake during training.
- Multi-Day Competitions: Swimmers need to focus on overall high carbohydrate intake throughout the competition, ensuring glycogen stores are topped off between events and at the end of the day.
The Role of Hydration Alongside Carbs
Despite being surrounded by water, swimmers sweat and can become dehydrated, which compromises performance. Hydration is intrinsically linked to carbohydrate metabolism; proper fluid levels are needed to transport nutrients and electrolytes to working muscles.
- Before: Hydrate well before your session by drinking water or an electrolyte drink.
- During: Keep a water bottle at the end of your lane and take sips during breaks. For longer sessions, a sports drink serves both hydration and fueling purposes.
- After: Post-swim rehydration is crucial. Weighing yourself before and after can help determine fluid loss, and you should aim to replace 150% of that fluid in the hours following.
Conclusion: Perfecting Your Mid-Swim Fueling
Determining how many carbs per hour of swimming you need is a personalized journey that requires practice and attention to your body's signals. For efforts lasting over an hour, actively fueling with 30-60 grams of fast-digesting carbohydrates per hour is a solid starting point, increasing to 90 grams for elite-level endurance events. Alongside this, consistent hydration and a diet rich in complex carbohydrates and protein for recovery are the pillars of peak swimming performance. Experiment during training to find the right products and timing that maximize your energy and minimize any stomach issues. With a well-planned nutrition strategy, you can confidently power through even the most demanding swim sessions.
Visit a resource from Sports Dietitians Australia for additional nutritional guidelines.
