Carbohydrate Timing for Swimmers and Triathletes

For swimmers and triathletes, every stroke and every stride counts. Just like a high-performance engine needs the right fuel, your body needs optimal nutrition to perform at its peak. When it comes to endurance sports, carbohydrates are king, but it's not just about what you eat, it's about when you eat it.

Strategic Carb Loading

Think of your body as a car with a gas tank. Before a long drive (or a tough swim), you want that tank full! This is where strategic pre-competition carbohydrate loading comes in.

Why Carbs Before a Swim?

Carbohydrates are stored as glycogen in your muscles and liver. This glycogen is your primary fuel source for high-intensity exercise. Having fully stocked glycogen stores means you can maintain power and endurance for longer without "hitting the wall."

Timing is Everything:

• 24-48 Hours Out: The Glycogen Supercompensation Phase. For longer events (like an Ironman or a multi-day swim meet), you might consider a proper carbohydrate loading phase. This involves gradually increasing your carbohydrate intake to around 8-12 grams per kilogram of body weight per day, while slightly tapering your training volume. This helps maximize glycogen stores. Focus on complex carbohydrates like whole grains, pasta, rice, potatoes, and fruits.

• 3-4 Hours Before: The Pre-Race Meal. This is your last significant opportunity to top off your energy stores. Aim for a meal that is rich in complex carbohydrates, moderate in protein, and low in fat and fiber to prevent digestive upset. Examples include oatmeal with fruit, a bagel with jam, pasta with a light sauce, or rice with lean protein.

• 1 Hour Before: A Quick Top-Up. If you're feeling hungry or need a final energy boost, a small, easily digestible carbohydrate snack can be beneficial. Think a banana, a piece of toast, or a small energy bar.

• 30 Minutes Before or Less: Simple Sugars if Needed. For very short, intense efforts, or if you're truly feeling low on energy right before a race, a small amount of simple carbohydrates (like a gel or a few sips of a sports drink) can provide quick energy. Be cautious not to overdo it, as some individuals can experience a "sugar crash" if consumed too close to the start.

Carbohydrates During Competition

For most standard pool swimming events, you won't need to consume carbohydrates during the race itself, as your pre-swim fuel should be sufficient. However, for longer open-water swims, multi-sport events like triathlons, or lengthy training sessions, mid-competition fueling becomes crucial.

When to Fuel During Competition:

• Beyond 60-90 Minutes: If your event or training session is expected to last longer than 60-90 minutes, your body will start to deplete its glycogen stores. This is the point where you need to start thinking about replenishing those carbs.

What to Consume and How Often:

• Sports Drinks: These are an excellent choice as they provide both carbohydrates and electrolytes, which are vital for hydration and preventing cramps. Aim for drinks with a carbohydrate concentration of 6-8%.

• Energy Gels: Compact and easy to consume, gels deliver a concentrated dose of carbohydrates. Always take gels with water to aid absorption and prevent stomach upset.

• Chews and Blocks: Similar to gels, these offer a convenient way to get carbohydrates, often with a slightly different texture and sometimes added electrolytes.

• Small, Easily Digestible Solids (for Triathletes): For the bike and run leg of a triathlon, some athletes prefer small pieces of fruit (like bananas), pretzels, or even small sandwiches. Experiment in training to see what your stomach can handle.

General Guidelines for Intake:

• 30-60 grams of carbohydrates per hour is a common recommendation for endurance events lasting over an hour. Some ultra-endurance athletes may tolerate higher amounts (up to 90 grams/hour), but this requires extensive gut training.

Practice Makes Perfect:

The most critical takeaway for both pre- and during-competition fueling is to practice in training! Your gut is trainable, just like your muscles. Experiment with different foods, drinks, gels, and timings during your long swims and brick workouts to discover what works best for your body. What feels good in training will likely feel good on race day!

Talk soon,

Dr. Sandra and Team