Energy Supply and the Effects of Exercise on the Body Quiz

Which of the following is the primary source of energy for muscle contractions during short, high-intensity exercise?

• Fat

• Carbohydrates

• Protein

• Vitamins

Answer explanation

1. Carbohydrates are the primary energy source during short, high-intensity exercises as they can be quickly broken down to provide energy.

What is the term for the process by which the body converts food into energy?

• 
  

• Metabolism

• • Digestion

• • Respiration

• Circulation

Answer explanation

1. Metabolism is the overall process of converting food into energy in the body.

Which energy system is predominantly used during a 100-meter sprint?

• 
  

• Aerobic System

• • Anaerobic Glycolysis

• • ATP-PC System

• Oxidative System

Answer explanation

1. The ATP-PC system provides immediate energy through the breakdown of phosphocreatine, making it ideal for short bursts of activity like sprints.

What effect does regular aerobic exercise have on the heart?

• • Increases resting heart rate

• Decreases stroke volume

• Increases heart size and strength

• Decreases cardiac output

Answer explanation

1. Regular aerobic exercise leads to an increase in heart size and strength, making it more efficient.

During prolonged exercise, which macronutrient becomes the primary source of energy after the initial glycogen stores are depleted?

• Carbohydrates

• Fats

• Proteins

• Minerals

Answer explanation

1. After glycogen stores are depleted, the body turns to fats as the primary energy source during prolonged exercise.

Which of the following best describes the term 'VO2 max'?

• The maximum volume of oxygen the body can utilize during exercise

• The maximum speed a person can run

• The maximum volume of blood the heart can pump per beat

• The maximum amount of air the lungs can hold

Answer explanation

1. VO2 max refers to the maximum amount of oxygen the body can use during exercise, indicating aerobic endurance.

• Lactic acid is produced during which type of exercise?
  

• Aerobic

• Anaerobic

• Flexibility

• Resistance

Answer explanation

1. Lactic acid is a byproduct of anaerobic metabolism, which occurs when the body exercises at high intensities without enough oxygen.

What is the role of mitochondria in muscle cells during exercise?

• 
  

• Store glycogen

• Produce ATP

• • Release calcium

• Transport oxygen

Answer explanation

1. Mitochondria are known as the powerhouses of the cell, producing ATP during exercise.

Which of the following statements best describes the role of the anaerobic glycolysis energy system?

• It provides energy for long-duration, low-intensity activities by utilizing oxygen to break down carbohydrates and fats.

• It quickly resynthesizes ATP for short bursts of activity, lasting up to 10 seconds, without the use of oxygen.

• It breaks down glucose into pyruvate, producing ATP without oxygen, for activities lasting up to 2 minutes.

• It relies on the continuous supply of oxygen to produce ATP through the Krebs cycle and electron transport chain for sustained activities.

Answer explanation

Anaerobic glycolysis is the energy system that breaks down glucose to form pyruvate and produces ATP without the use of oxygen. This system is predominantly used during moderate to high-intensity activities that last from about 10 seconds to 2 minutes. When pyruvate is formed, it can either enter the mitochondria for further energy production if oxygen is available or be converted into lactate when oxygen is insufficient, which is common in high-intensity activities. This system bridges the gap between the immediate ATP-PC system and the longer-lasting aerobic energy system.

Which energy system is primarily responsible for ATP production during prolonged, low-intensity activities such as marathon running?

• Phosphagen (ATP-PC) system

• Anaerobic glycolysis

• Aerobic energy system

• Lactic acid system

Answer explanation

The aerobic energy system is the primary energy system used during prolonged, low-intensity activities like marathon running. This system relies on the continuous supply of oxygen to produce ATP through the complete oxidation of carbohydrates, fats, and sometimes proteins. The process involves glycolysis, the Krebs cycle, and the electron transport chain, which work together to generate a large amount of ATP necessary for sustained activities. Unlike anaerobic systems, the aerobic system can provide energy for extended periods, making it ideal for endurance events.