In IB Sports, Exercise and Health Science (SEHS), macronutrients are studied to explain how the body fuels exercise, supports recovery, and adapts to training. The three main macronutrients are carbohydrates, fats, and proteins, and each plays a distinct role in exercise performance and health.
Understanding the function of each macronutrient allows students to explain energy use, fatigue, and recovery clearly in exam answers.
Carbohydrates: Primary Fuel for Exercise
Carbohydrates are the body’s preferred energy source during moderate to high-intensity exercise. They are stored as glycogen in muscles and the liver and are broken down to produce ATP.
Key roles of carbohydrates include:
- Providing rapid energy
- Supporting endurance performance
- Allowing higher exercise intensities
In IB SEHS, carbohydrates are strongly linked to fatigue prevention and endurance capacity. When carbohydrate stores are low, performance declines significantly.
Fats: Long-Term Energy Source
Fats provide a large and efficient energy reserve, particularly during low to moderate-intensity exercise. They are broken down more slowly than carbohydrates but can supply energy over long durations.
Important features of fats include:
- High energy yield per gram
- Primary fuel at lower intensities
- Important role in prolonged exercise
Although fats are essential, they cannot support high-intensity exercise as effectively as carbohydrates due to slower energy release.
Proteins: Repair and Recovery
Proteins are not a primary energy source during exercise. Instead, their main role is supporting growth, repair, and adaptation.
Key functions of proteins include:
- Repairing damaged muscle tissue
- Supporting muscle growth
- Aiding recovery after training
In IB SEHS, protein is often discussed in the context of recovery and training adaptation rather than energy production.
Macronutrients and Exercise Balance
Effective performance depends on balancing all three macronutrients. Carbohydrates fuel exercise, fats support longer-duration activity, and proteins help the body recover and adapt.
In exams, students should avoid stating that one macronutrient is “better” than others. High-mark answers explain when and why each macronutrient is used.
Exam Relevance for IB SEHS
Macronutrient questions often require comparison and application. Students should clearly link each nutrient to exercise intensity, duration, and recovery. Using correct terminology and avoiding oversimplification is essential.
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Frequently Asked Questions (FAQs)
Which macronutrient is most important for endurance exercise?
Carbohydrates are most important for sustaining moderate to high-intensity endurance exercise because they provide fast and efficient energy.
Why aren’t proteins a main energy source?
Proteins are mainly used for tissue repair and recovery. They only contribute minimally to energy production during exercise.
How are macronutrients tested in IB SEHS exams?
Questions often require students to compare macronutrients, explain energy use at different intensities, and apply knowledge to performance scenarios.
