Chapter 2

Question 1

Name at least three forms of energy

Answer 1

Chemical Energy, Mechanical Energy, Heat Energy

Examples of energy transfer: Carbs → ATP for muscle contraction (mechanical), ATP breakdown → heat energy for body temperature regulation.

Question 2

Is ATP ever used up completely by exercising muscle?

Answer 2

No, ATP is never fully depleted

A small reduction in ATP can impair muscle function, leading to mechanisms that rapidly regenerate ATP.

Question 3

How does the muscle respond to reduced ATP concentrations?

Answer 3

Activates energy systems to replenish ATP:
* Creatine phosphate System
* Anaerobic Glycolysis
* Aerobic System

Question 4

What is the most commonly used unit of measure for energy in nutrition?

Answer 4

Kilocalorie (kcal)

In the SI system, joules (J) are the standard measure of energy.

Question 5

How is the energy content of food determined?

Answer 5

Using a bomb calorimeter

Measures the heat released when food is burned.

Question 6

What is the energy content of carbohydrates?

Answer 6

4 kcal/g

Question 7

What is the energy content of proteins?

Answer 7

4 kcal/g

Question 8

What is the energy content of fats?

Answer 8

9 kcal/g

Question 9

What is the energy content of alcohol?

Answer 9

7 kcal/g

Question 10

How is energy expenditure measured by direct calorimetry?

Answer 10

By assessing heat production in a calorimeter chamber

Measures total energy expenditure based on heat produced by the body.

Question 11

What is indirect calorimetry?

Answer 11

Estimates energy expenditure by measuring VO₂ and VCO₂

Based on the principle that energy metabolism requires oxygen and produces CO₂.

Question 12

What does RER stand for?

Answer 12

Respiratory Exchange Ratio

Question 13

What does an RER value of 0.70 indicate?

Answer 13

Predominantly fat oxidation

Question 14

What does an RER value of 1.00 or higher indicate?

Answer 14

Predominantly carbohydrate oxidation or anaerobic metabolism

Question 15

What is the Doubly Labeled Water Method (DLW)?

Answer 15

Measures CO₂ production using water labeled with stable isotopes

Considered the gold standard for measuring free-living energy expenditure.

Question 16

What is the energy balance equation?

Answer 16

If Energy In > Energy Out → Weight gain; If Energy In < Energy Out → Weight loss

Question 17

What are the three components of ‘energy out’?

Answer 17

Resting Metabolic Rate (RMR), Thermic Effect of Food (TEF), Physical Activity Energy Expenditure (PAEE)

Question 18

What percentage of daily energy expenditure does RMR account for?

Answer 18

~70%

Question 19

What is Resting Metabolic Rate (RMR)?

Answer 19

The amount of energy expended at rest to sustain basic physiological functions

Question 20

Which factors influence RMR?

Answer 20

Body Composition, Age, Sex, Genetics, Hormones, Temperature & Climate, Fasting/Dieting, Exercise & Training

Question 21

What has the greatest influence on RMR?

Answer 21

Lean body mass (muscle mass)

Question 22

How accurate are prediction equations for estimating RMR?

Answer 22

Standard prediction equations can be off by ±10-20%

More precise methods include indirect calorimetry.

Question 23

What activity factor is used for a sedentary individual?

Answer 23

1.2

Question 24

What activity factor is used for a professional rugby player?

Answer 24

2.5 - 3.0+

Question 25

What is the most accurate way of measuring total daily energy expenditure (TDEE)?

Answer 25

Doubly Labeled Water (DLW)

Question 26

What is the most practical method for measuring TDEE in a university setting?

Answer 26

Indirect Calorimetry and Prediction Equations + Activity Logs

Question 27

What is the estimated kcal needs for a soccer player in practice for 2-3 hours a day?

Answer 27

~3,500 - 4,500 kcal/day

Question 28

What are the energy factor estimates for an athlete recovering from a broken leg?

Answer 28

1.2 - 1.3

Question 29

What are the estimated kcal needs for an athlete training for an Ironman?

Answer 29

~5,000 - 8,000 kcal/day