Questions and Answers
What is the primary focus of sports nutrition?
Which of the following is NOT one of the six vital nutrients?
What role do carbohydrates, proteins, and fats play in sports nutrition?
What is the main function of adenosine triphosphate (ATP) in the body?
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Which of the following best describes an athlete in the context of sports nutrition?
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What is a primary factor contributing to muscle fatigue during high-intensity, short-duration exercise?
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How does low-intensity, long-duration exercise typically lead to muscle fatigue?
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Which strategy is NOT typically recommended to delay the onset of muscle fatigue?
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After extreme-duration exercise, such as running a marathon, how long may recovery take?
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Which factor is primarily responsible for rapid muscle fiber fatigue when continuously stimulated?
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Which factors most significantly impact an athlete's energy requirements?
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What is the relationship between energy intake and energy expenditure?
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Which component of energy expenditure accounts for the largest percentage of daily total energy expenditure?
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What is the typical contribution of physical activity to total energy expenditure?
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Which macronutrient has the highest thermic effect on energy expenditure?
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What energy system primarily utilizes glucose to produce energy without requiring oxygen?
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Which substrate primarily fuels low-intensity exercise lasting up to 2 hours?
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What is the effect of endurance training on fat utilization during exercise?
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What is a significant factor affecting an athlete's capacity to exercise at high intensities for prolonged periods?
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How does the body primarily generate energy during moderate-intensity exercise?
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What effect does carbohydrate loading have on muscle glycogen content?
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What is the primary consequence of inadequate glucose supply during exercise?
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Which energy source is primarily utilized at high exercise intensity (65% to 85% VO₂ max)?
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Which activity factor range describes a low active lifestyle?
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How much additional energy expenditure can training or competition increase daily energy needs?
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Which muscle type is primarily used for aerobic endurance events?
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What is the respiratory quotient (RQ) value for carbohydrates?
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What is a common measurement used to assess the maximum capacity of oxygen consumption during exercise?
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Which of the following factors can impact the energy expenditure of an endurance athlete?
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What is the primary function of the ATP-CP energy system?
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What is the caloric expenditure range for endurance athletes during exercise?
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Study Notes
Nutrition in Sports and Fitness
- Sports nutrition applies nutritional knowledge to optimize athletic performance and recovery.
- Athletes encompass a spectrum from casual fitness enthusiasts to competitive professionals.
Energy Requirements for Exercise
- Energy balance formula: Total energy intake (EI) equals total energy expenditure (TEE).
- Energy intake includes all food and beverages consumed.
- Total energy expenditure (TEE) comprises basal metabolic rate (BMR), thermic effect of food (TEF), and thermic effect of activity (TEA).
Components of Energy Expenditure
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Basal Metabolic Rate (BMR):
- Accounts for 50%-70% of daily energy expenditure.
- Measured in a postabsorptive state in a thermoneutral environment.
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Thermic Effect of Food (TEF):
- Varies for macronutrients: 20%-30% for proteins, 5%-10% for carbohydrates, and 0%-5% for fats.
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Physical Activity:
- Contributes 20%-40% to total energy expenditure.
- Influenced by activity type, duration, intensity, and frequency.
Energy Systems
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ATP-CP (Phosphagen) System:
- Provides a quick energy source for immediate ATP needs, lasting 10-25 seconds during strenuous activity.
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Lactic Acid System:
- Breaks down glucose without oxygen; lactic acid accumulation leads to muscle fatigue.
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Aerobic System:
- Utilizes carbohydrates and fats for sustained energy; requires oxygen and produces ATP at a slower rate.
Muscle Types and Energy Sources
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Type I Muscle Fibers:
- "Red" fibers for aerobic endurance, rich in mitochondria, utilize glucose and fatty acids.
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Type II Muscle Fibers:
- "White" fibers; Type IIa is hybrid, and Type IIb specializes in short-duration, high-power activities.
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Major energy sources during exercise include muscle glycogen, plasma glucose, fatty acids, and intramuscular triacylglycerols.
Fuel Sources and Exercise Intensity
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Fuel source shifts with intensity:
- Low intensity relies on plasma fatty acids; moderate intensity increases fatty acid oxidation; high intensity sees increased carbohydrates use and lactate production.
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Endurance training enhances fat oxidation and glycogen sparing effects.
Carbohydrate Supplementation
- Essential for sustaining high-intensity exercise; muscle glycogen is crucial during activities above 70% VO₂ max.
- Carbohydrate loading increases glycogen stores before competitions.
Fatigue Mechanisms
- Muscle fatigue is linked to inadequate glucose supply; reducing intensity can help manage fatigue.
- High-intensity exercise produces lactic acid, lowering muscle pH and impairing performance.
- Low-intensity, prolonged exercise may lead to fatigue developing gradually, impacted by muscle recovery rate.
Strategies to Delay Fatigue
- Carbohydrate loading and adequate hydration.
- Implementing effective training techniques and recovery strategies.
- Considering ergogenic aids to enhance performance.
Summary
- Sports nutrition is vital for maximizing performance and recovery, emphasizing the correct balance and timing of nutrient intake to meet the specific energy demands of different activities.
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Description
This quiz explores the fundamentals of sports nutrition, focusing on the nutritional needs of athletes and the importance of various nutrients. You'll learn about energy expenditure, the human energy systems, and the impact of nutrition on performance and fatigue. Test your understanding of how nutrition supports fitness and athletic activities.
