Practical Nutrition Guide for Athletes

It is essential to understand the importance of proper nutrition for optimal performance during training and racing. Fueling your body correctly can make the difference between a personal best and pushing yourself to the limit.

Our bodies primarily use two sources of energy: Glycogen and Fat

Glycogen : Glucose stored in the liver and muscles. It is our body’s easily accessible fuel source, especially during high-intensity exercise. 
Fat : Stored in adipose tissue. It is a more efficient energy source for low-intensity, long-duration exercise.

The Change: From Glycogen to Fat

The body switches between these energy sources depending on the intensity and duration of exercise. During high intensity exercise, Zone 3 and above, the body relies primarily on glycogen. As exercise intensity decreases or duration increases, the body gradually switches to using more fat for fuel. This is known as the “Fat Burning Zone.” Zone 1 and 2.

Carbohydrate Intake:

The recommended carbohydrate intake varies depending on the duration and intensity of the exercise:

Less than 60 minutes: For shorter workouts, your body’s glycogen stores are usually sufficient. Additional carbohydrate consumption is usually not necessary.

60-120 minutes: Moderate intensity workouts in this range can benefit from carbohydrate intake during exercise, especially if the intensity is high. Aim for 30-60 grams of carbohydrate per hour.

3+ hours: For longer endurance events, consistent carbohydrate intake is crucial to maintain energy levels and prevent “hitting the limit.” Aim for 60-90 grams of carbs per hour.

Areas of Fat Use

The body primarily uses fat for fuel during low to moderate intensity exercise, usually at a heart rate in Zone 1 and 2. However, it is important to note that even during low intensity exercise, the body still uses some glycogen for fuel.

Key Nutritional Strategies for Endurance Athletes

Carbohydrate loading: For events lasting longer than 90 minutes, carbohydrate loading can help maximize glycogen stores.

Hydration: Proper hydration is essential for optimal performance. Dehydration can significantly impair performance and increase the risk of heat-related illness.

Electrolyte Replacement: Sweat loss during exercise can lead to electrolyte imbalances. Replacing electrolytes, such as sodium and potassium, is crucial, especially in hot and humid conditions.

Post-workout nutrition/recovery guidelines

• Glycogen recovery rates may be higher during the first few hours after exercise. You can take advantage of this to enhance recovery by consuming carbohydrate-rich foods in the hours after exercise.
• This is particularly important after high intensity or long duration sessions that rely heavily on carbohydrates for fuel.
• Not every session will deplete glycogen stores (for example, a light 45-minute workout will have a high reliance on fat for energy), but fueling properly will help avoid situations where you under-exert calories on successive days, resulting in low energy levels and poor performance.
• How much carbohydrate? 1 to 1.2 g of carbohydrate per kilogram of body weight per hour within the first 2 hours after training.

Repair Nutrition

• Ingesting protein after all training sessions is a key part of the recovery process. Typically, protein is considered in the context of strength training to facilitate muscle growth. But protein provides the amino acids that are the building blocks to not only repair and rebuild damaged tissue, but also to help muscles adapt to training. A desired goal of aerobic training is to create more mitochondria in the muscle, and the amino acids in the protein we consume are critical to facilitating that.
• Including protein with carbohydrates in your post-high intensity or long-duration workout meals is optimal. This is because the combination of carbohydrates and protein actually increases the rate of muscle glycogen recovery. An excellent option in this case is to consume 400-500 ml of chocolate milk within 30 minutes of completing a long-duration workout..
• How Much Protein? 20 to 40g of protein in the first 2 hours after training.

Rehydration

• Sodium will also have been lost through sweat during a session, so sodium should also be consumed, either as part of an electrolyte/sports drink or within food during the post-exercise meal. This helps the body to absorb and retain the fluids being consumed.
• You should consume fluids to help replace the fluid and electrolytes lost through sweat during the session.
• • Rehydration should be more aggressive when sweat losses have been high during a session, if you have to train (or compete) again within a short period of time after the initial exercise.
• How much fluid? 150% of the fluid you have lost during training.

By understanding these key principles and implementing them into your training and competition strategies, you can optimize your performance and achieve your goals.

If you need help with your training or need a Coach to prepare you for your next challenge, send me a message and I will be happy to help you.

Andrés Sauma
Ironman U Certified Coach

Tridot Coach