By studying this chapter, you should be able to do the following:

Express work, power, and energy in standardized (SI) units and convert those units to others commonly used in exercise physiology.

Give a brief explanation of the procedure used to calculate work performed during step, cycle ergometer, and treadmill exercise.

Describe the concept behind the measurement of energy expenditure using (a) direct calorimetry and (b) indirect calorimetry.

Calculate the following expressions of energy expenditure when given the oxygen uptake in liters per minute: kcal · min

^{−1}, ml · kg^{−1}· min^{−1}, METs, and kcal · kg^{−1}· hr^{−1}.Estimate energy expenditure during horizontal treadmill walking and running, and cycle ergometry.

Describe the procedure used to calculate net efficiency during steady-state exercise; distinguish efficiency from economy.

Units of Measure 17

Metric System 17

SI Units 17

Work and Power Defined 17

Work 17

Power 18

Measurement of Work and Power 18

Bench Step 18

Cycle Ergometer 19

Treadmill 20

Measurement of Energy Expenditure 21

Direct Calorimetry 21

Indirect Calorimetry 22

Common Expressions of Energy Expenditure 23

Estimation of Energy Expenditure 24

Calculation of Exercise Efficiency 25

Factors That Influence Exercise Efficiency 26

Running Economy 27

cycle ergometer

direct calorimetry

ergometer

ergometry

indirect calorimetry

kilocalorie (kcal)

MET (metabolic equivalent)

net efficiency

open-circuit spirometry

percent grade

power

relative $V\u02d9O2$

System International (SI) units work

How much energy do you expend when you run a mile? How fast can you run 100 m? How high can you jump? These questions deal with energy, speed, and explosive power—and so will you as you study exercise physiology. Throughout this text, we will discuss such terms as *aerobic and anaerobic power*, *efficiency*, *work capacity*, and *energy expenditure*. The purpose of this chapter is to introduce you to some of the most common pieces of equipment and measurements linked to these terms. It is very important to understand this information at the outset, as it is used throughout the text. However, the details associated with specific exercise tests for fitness and performance are covered in detail in Chaps. 15 and 20. Let’s begin with the most basic units of measurement.

In the United States, the English system of measurement remains in common use. In contrast, the metric system, which is used in most countries, is the standard system of measurement for scientists and is used by almost all scientific journals. In the metric ...