Energy Supply for Athletic Performance

Energy supply is the foundation for achieving high levels of athletic performance. It involves the process of obtaining and utilizing energy through the metabolism of macronutrients (carbohydrates, fats, and proteins). A well-balanced diet is

Nutrition is a critical factor in an athlete’s ability to perform well. Studies show that inadequate nutrient intake can negatively impact an athlete’s performance, recovery, and progress​. Carbohydrates, being the primary energy source for high-intensity workouts, are essential for muscle function. A balanced intake of macronutrients allows athletes to perform optimally throughout different phases of training and recover more effectively​.

The body utilizes three main substrates to supply energy for physical activity:

1. Carbohydrates — The primary energy source during high-intensity exercise. Glycogen, stored in muscles and the liver, is broken down into glucose to fuel the muscles during workouts. Research suggests that carbohydrate loading before endurance events can enhance glycogen stores and improve performance​.
2. Fats — Fats are used as a source of energy during prolonged, moderate-intensity exercise. While high-fat diets can increase the body’s ability to oxidize fat, they may not always lead to improvements in sports requiring high intensity​.
3. Proteins — While proteins are not the primary source of energy, they play a key role in muscle recovery and repair. Sufficient protein intake is critical for maintaining muscle mass and promoting tissue repair​.

Each type of physical activity relies on different energy systems, depending on the duration and intensity of the effort:

1. Anaerobic Alactic System — This system provides energy for short bursts of explosive activity (1−4 seconds), such as jumps or heavy weightlifting. The primary energy source here is adenosine triphosphate (ATP).
2. Anaerobic Alactic System with Creatine Phosphate — For activities lasting 4−20 seconds, the body uses stored creatine phosphate to replenish ATP. This system is critical for sports like sprinting and powerlifting​.
3. Anaerobic Lactic System — For high-intensity efforts up to 60 seconds, the body uses rapid glycolysis to break down carbohydrates for energy. This process also produces lactic acid, which can lead to muscle fatigue​.
4. Aerobic System — For activities lasting over 180 seconds, the body shifts to aerobic metabolism, utilizing both carbohydrates and fats as energy sources. While fat oxidation is efficient for low- to moderate-intensity exercise, it is insufficient to meet the energy demands of prolonged, high-intensity activity. Therefore, carbohydrates (glycogen) become increasingly important during extended high-intensity efforts​. Research shows that fats and glycogen work synergistically to fuel endurance exercise, especially during events like marathons​.

Glycogen is the primary form of carbohydrate storage in the body, stored in muscles and the liver. During physical exertion, it breaks down into glucose, which fuels muscle activity. In aerobic exercise, glycogen reserves become depleted, particularly when the intensity is high. Carbohydrate loading before endurance events helps maximize glycogen storage and improve performance​.

The recovery of energy substrates after exercise varies based on the type of substrate and the intensity of the exercise:

• Creatine Phosphate – Replenished within 2–5 minutes.
• Muscle Glycogen – Takes between 5 and 46 hours to fully recover.
• Liver Glycogen – Takes 12 to 24 hours to replenish.

Proper nutrition before, during, and after training aids in speeding up recovery​.

A common misconception is that post-exercise muscle soreness is caused by lactic acid buildup. In reality, lactic acid is cleared from the body within 30−60 minutes after exercise, while muscle soreness results from micro-tears in muscle fibers, which promote growth and strength​.

Nutrition plays a critical role in maintaining athletic performance, recovery, and adaptation to training. Different energy systems are activated based on the type and intensity of exercise, and each system requires a unique combination of macronutrients. Fats and carbohydrates work together during long-duration exercise, and proper nutrition is essential for replenishing energy stores, thus enabling athletes to achieve peak performance​.

Don’t let the 'athlete's wall' hold you back from reaching your full potential. With the right nutrition and hydration strategies, you can power through every workout and recover faster. Take control of your training today—get personalized nutrition recommendations tailored to your goals and performance needs. Fuel your performance now!