Summarizing Results Heartrates

Kiera27

Comparing_the_energy_expenditure.pdf

Home >Mathematics homework help >Statistics homework help >Summarizing Results Heartrates

COMPARING THE ENERGY EXPENDITURE AND RATING OF PERCEIVED EXERTION OF VARIOUS EXERCISE MODES AT A SPECIFIC HEART RATE

A Thesis

Presented to the

Faculty of

California State University, Fullerton

In Partial Fulfillment

of the Requirements for the Degree

Master o f Science

Kinesiology

Julie Lyn Smith

Approved by:

Dr. William Beam, Committee Chair Department of Kinesiology

U - — f. Jared Cobum, Member a

Department of Kinesiology /

Dr. Lee Brown, Member Department of Kinesiology

Date

7 ( 7 Date

7 - 2 - . - O ' ) Date

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

U MI N u m b e r: 1 4 448 80

Smith, Julie Lyn

INFORMATION TO USERS

The quality of this reproduction is dependent upon the quality of the copy

submitted. Broken or indistinct print, colored or poor quality illustrations and

photographs, print bleed-through, substandard margins, and improper

alignment can adversely affect reproduction.

In the unlikely event that the author did not send a complete manuscript

and there are missing pages, these will be noted. Also, if unauthorized

UMI UMI Microform 1444880

unauthorized copying under Title 17, United States Code.

ProQuest Information and Learning Company 300 North Zeeb Road

P.O. Box 1346 Ann Arbor, Ml 48106-1346

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

ABSTRACT

Aerobic exercise is one o f the key elements for the elimination of obesity, which

is a national health problem. Presently, there is limited research on energy expenditure

and rating of perceived exertion (RPE) when comparing the elliptical machine, treadmill,

and cycle ergometer. The purpose of this study was to compare the energy expenditure,

oxygen uptake, and RPE of various modes of exercise at three specific heart rates (100

bpm, 130 bpm, and 160 bpm).

Twenty healthy, recreationally active men and women between the ages of 18 and

29 participated in this randomized, two-week study. While exercising, participants were

connected to a metabolic cart to measure metabolic responses and wore a Polar heart rate

monitor to record heart rate. Participants completed all three exercise trials in random

order. During each exercise test trial, they started slowly to keep their heart rate at 100

bpm and remained at a steady state for energy expenditure, oxygen uptake, and RPE to be

recorded. Resistance exercise intensity was increased to 130 bpm and 160 bpm,

respectively.

Heart rates fell within five beats of the intended range, with no significant

differences at any range for the three modes. There was no significant effect for mode in

oxygen uptake or energy expenditure, but there was a significant effect for gender, with

men having significantly greater values than women for both variables. There was no

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

significant effect due to gender for RPE, but there was a significant main effect due to

mode of exercise, with the cycle ergometer yielding a significantly greater RPE at a heart

rate of 160 bpm than either o f the other two modes. The elliptical machine and treadmill

are recommended over the cycle ergometer for fitness improvements and weight loss due

to their ability to expend energy at a lower RPE in most people.

111

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

TABLE OF CONTENTS

ABSTRACT.................................................................................................................. ii

LIST OF TABLES........................................................................................................ vi

ACKNOWLEDGMENTS............................................................................................ vii

Chapter 1. INTRODUCTION............................................................................................... 1

Problem Statement............................................................................................... 2 Purpose of the Study............................................................................................ 2 Hypothesis........................................................................................................... 3 Significance......................................................................................................... 3 Operational Definitions........................................................................................ 3 Delimitations........................................................................................................ 5 Limitations........................................................................................................... 6

2. LITERATURE REVIEW.................................................................................... 7

Benefits of Physical Activity............................................................................... 7 Exercise Modes.................................................................................................... 8 Maximal Oxygen Consumption........................................................................... 9 Heart R ate............................................................................................................ 9 Rate o f Perceived Exertion.................................................................................. 10 Research Studies.................................................................................................. 10 Summary.............................................................................................................. 20

3. METHODS.......................................................................................................... 21

Participants........................................................................................................... 21 Instruments and Measures................................................................................... 21 Procedures............................................................................................................ 22 Design and Statistical Analysis............................................................................ 24

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

4. RESULTS............................................................................................................ 25

Heart R ate............................................................................................................ 25 Oxygen Uptake.................................................................................................... 25 Energy Expenditure............................................................................................. 26 Rate of Perceived Exertion (RPE)....................................................................... 26

5. DISCUSSION...................................................................................................... 29

Energy Expenditure............................................................................................. 29 Oxygen Uptake.................................................................................................... 30 Rate of Perceived Exertion (RPE)....................................................................... 30

APPENDIX................................................................................................................... 33

A. Consent Form................................................................................................ 33 B. Exercise Risk Assessment............................................................................ 39 C. Questionnaire................................................................................................ 42 D. Appointment Reminder................................................................................. 43 E. RPE Instructions........................................................................................... 44

REFERENCES ............................................................................................................ 45

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

LIST OF TABLES

Table Page

1. Descriptive Statistics....................................................................................... 27

2. Results by mode and by gender...................................................................... 28

Reproduced with permission of the copyright owner. Further reproduction prohibited w ithout permission.

ACKNOWLEDGEMENTS

I would like to express my gratitude to my committee members Dr. Jared Cobum

and Dr. Lee Brown for their support and encouragement during my thesis study. I

especially thank my committee chairman, Dr. William Beam, for his patience, wisdom,

knowledge, guidance, and unwavering belief in me. I appreciated him making time for

me in spite o f his busy schedule, and his humor when I was frustrated. Additionally, I am

grateful to my fellow graduate students, Connie Grant, Shawn Olmstead, and Krystle

Rapisura, for their friendship and assistance in the lab. Lastly, I acknowledge my parents

for their unconditional love and moral support. Without them, this would not have been

possible.

vii

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

CHAPTER 1

INTRODUCTION

People participate in aerobic exercise to enhance health status, alter body

composition, reduce disease risk, and increase fitness (Kravitz & Vella, 2002). Various

exercise modes result in different energy expenditures. Varying the intensity o f exercise

is best for cardiovascular benefits. Running on a treadmill, pedaling on a cycle

ergometer, and exercising on an elliptical machine are three different modes o f aerobic

exercise. More energy is expended when participating in a weight-bearing activity, such

as walking or running, compared to non-weight bearing activities like cycling (Kravitz &

Vella, 2002). Elliptical trainers are weight-bearing, non-impact machines that feature a

“fluid” lower body elliptical motion (Batte, Darling, Evans, Lance, Olson, & Pincivero,

2003).

Maximal oxygen consumption (VO2 max) is the highest rate at which oxygen can

be taken up and consumed by the body during intense exercise (Bassett & Howley,

2000). It is a measure o f fitness and health (Bassett & Howley, 2000). There is a linear

relationship between heart rate and VO2 during exercise. Heart rate is used to estimate

exercise intensity and prescribe exercise (Crouter, Albright, & Bassett, 2004). Rate of

perceived exertion (RPE) is based on the 15 point Borg scale (6-20) and is the subjective

intensity of effort, strain, discomfort, and fatigue during intense exercise.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Recent research reported that the treadmill and elliptical machine were similar in

the amount of energy expended at the same exercise intensity and RPE (Porcari, Zedaker,

Naser, & Miller, 1998; Green, Crews, Pritchett, Mathfield, & Hall, 2004). Other studies

determined that the mode o f exercise did not matter as long as participants exercised at a

high intensity (Glass & Chvala, 2001; Egana & Donne, 2004).

Problem Statement

Aerobic exercise is one o f the key elements for the elimination of obesity, which

is a national public health problem. The mission of the American College o f Sports

Medicine (ACSM) is to encourage the public to participate in physical activity and fitness

(Whaley, 2006). In 1998, it was estimated that 40% of adults did not participate in

physical activity (Whaley, 2006). Presently, there is no conclusive research on energy

expenditure and rating o f perceived exertion when comparing the elliptical machine,

treadmill, and cycle ergometer.

Purpose of the Study

The purpose of the study was to compare the energy expenditure and the rate of

perceived exertion (RPE) of various modes o f exercise (treadmill, elliptical machine, and

cycle ergometer) at three specific heart rates (100, 130, and 160 beats per minute). If

people were more aware o f the most efficient exercise mode resulting in the highest

energy expenditure, they may be more inclined to exercise and adhere to an appropriate

exercise program.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Hypothesis

1) The energy expenditure of the treadmill will be similar to that o f the elliptical

machine, but will be significantly higher than the energy expenditure o f the cycle

ergometer (at the heart rates of 100,130, and 160 beats per minute).

2) The RPE of the cycle ergometer will be significantly higher than the elliptical

machine and treadmill (at heart rates of 100,130, and 160 beats per minute).

Significance

Research studies measuring the energy expenditure of elliptical machines are

limited. Since the elliptical machine is a fairly new exercise modality, there is not as

much research on it compared to the treadmill and cycle ergometer. No studies have

been administered where the energy expenditure and RPE of three modes of exercise

was recorded at specific heart rates. People should be taught about which modes of

exercise have the highest energy expenditure and the greatest cardiovascular benefits.

Operational Definitions

■ Borg Scale: The scale (6-20) used to measure rate of perceived exertion

(RPE) during exercise (Whaley, 2006).

■ Cycle ergometer: A stationary bicycle that measures the power of the rider

against a form o f resistance (Paton & Hopkins, 2001).

■ Elliptical machine: A low-impact exercise modality that allows the feet to

move in a cyclic pattern that is similar to running kinematics (Mercer, Dufek,

& Bates, 2001).

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

■ Energy expenditure: the amount of energy expended (calories burned) during

exercise as measured by a metabolic cart (Kravitz & Vella, 2002).

■ Heart rate: The number of heart contractions per unit of time (Thomas, 1997).

It is used to estimate intensity and prescribe exercise (Crouter, Albright, &

Bassett, 2004).

■ Heart rate monitor: A device strapped around the chest, used to record heart

rate during exercise, as well as estimate energy expenditure (calories burned)

(Crouter, Albright, & Bassett, 2004).

■ Maximal oxygen consumption (VO2 max): The highest rate at which oxygen

can be taken up and consumed by the body during intense exercise. It is a

measure of fitness and health and is most commonly performed on a treadmill

or cycle ergometer (Bassett & Howley, 2000).

■ Rate of perceived exertion (RPE): The subjective intensity of effort, strain,

discomfort, and fatigue, felt during exercise. Based on the 15-point Borg

scale from 6 to 20. It is used to observe maximal exertion during physical

activity (Whaley, 2006; Moyna, Robertson, Meckes, Peoples, Millich, &

Thompson, 2000).

■ Treadmill: Motor driven treadmills are used for maximal and submaximal

exercise testing. Running and walking tests can be conducted. Sedentary and

fit participants can use the treadmill (Whaley, 2006).

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

D elim itation s

Participants were twenty apparently healthy men and women, between the ages of

18 and 29, who were at low risk for heart disease according to the American College

of Sports Medicine. They were recreationally active, which was defined as

participating in aerobic exercise two or more times per week in the previous three

months. Participants were recruited from California State University, Fullerton

Kinesiology classes to volunteer in the study. Low risk was defined as men under the

age o f 45 and women under the age of 55, who are asymptomatic and have one risk

factor or less (Whaley, 2006). Risk factors include:

1) Family history of myocardial infarction, coronary revascularization, sudden death

before the age o f 55 years in a father or other male first degree relative, or before

65 years of age in a mother or other female first-degree relative.

2) Current cigarette smoker or has quit in the previous 6 months.

3) Hypertension with a systolic blood pressure o f > 140 mm Hg or a diastolic blood

pressure of > 90 mm Hg.

4) Dyslipidemia: Low-density lipoprotein (LDL) cholesterol >130 mg/dL or high

density lipoprotein (HDL) cholesterol < 40 mg/dL, or on lipid-lowering

medication, or if total serum cholesterol is > 200 mg/dL.

5) Impaired fasting glucose: Fasting blood glucose >100 mg/dL.

6) Obesity: Body mass index > 30 kg/m, or waist girth >102 cm. for men and > 88

cm for women, or waist to hip ratio > 0.95 for men and > 0.86 for women.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

7) Sedentary lifestyle: Not participating in regular exercise or not meeting the

minimal physical activity recommendations from the U.S. Surgeon General’s

Report.

Other exclusionary criteria include chronic asthma and cardiovascular problems.

Limitations

Limitations to the study were small sample size and the use of self-report to

define the term “recreationally active.”

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

CHAPTER 2

LITERATURE REVIEW

This literature review presents a broad base of knowledge regarding aerobic

activity, exercise modes, energy expenditure, maximal oxygen consumption, and heart

rate during exercise. The topics addressed are maximal oxygen consumption during

maximal and submaximal exercise testing utilizing the treadmill, cycle ergometer, and

elliptical trainer, and measuring the energy expenditure, monitoring heart rate, and rating

of perceived exertion (RPE) during exercise.

Benefits of Physical Activity

Health-related components o f fitness are linked to health promotion and disease

prevention, which include cardiovascular endurance, muscular strength and endurance,

flexibility, and body composition. Moderate-intensity physical activity has been

suggested to receive health benefits (Whaley, 2006). The Surgeon General’s Report,

Physical Activity and Health, stated that individuals can benefit from a moderate amount

of physical activity most days o f the week by walking briskly for 30 minutes, or running

for 15 minutes. Increased physical activity for longer periods of time yield more health

benefits. The Surgeon General recommended that people participate in light to moderate

exercise most days of the week (U.S. Department o f Health and Human Service, 2006).

ACSM proposed in 2001, that overweight people exercise at least 45 minutes a day to

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

prevent weight gain or lose weight. However, the Institute of Medicine (IOM) and

International Association for the Study o f Obesity (IASO) have promoted exercising 60

to 90 minutes a day. According to ACSM, an optimal dose-response relationship has not

been decided yet; however, the more a person exercises, the more health benefits they

will receive (2006).

Exercise and physical activity prevent cardiac problems, hypertension, and certain

cancers, decrease the occurrence of stroke, and obesity (Whaley, 2006). Physically active

people have lower rates o f disease and mortality compared to sedentary people. The

minimal dose of physical activity needed to obtain disease risk reductions is uncertain

(Whaley, 2006).

Exercise Modes

When choosing an exercise mode people should take into account personal

interest, risk of injury, facility availability, and fitness goals (Kravitz & Vella, 2002).

Energy expenditure can be maximized by varying the intensity of exercise, using a

machine that can be graded and adjusted. Running expends more calories than walking

due to the increased intensity of the activity, but both result in positive health benefits

(Kravitz & Vella, 2002). The elliptical machine has become a popular choice for low-

impact, cardiovascular exercise and is beneficial to people with injuries and weight

problems (Dalleck, Kravitz, & Robergs, 2004). During exercise at a self-selected

intensity, Cook, Heelan, and Kruegar (2004) determined that college-aged men and

women who exercised on an elliptical machine and treadmill had similar energy

expenditures. However, Wallace, Sforzo, and Swensen (2004) found that the treadmill

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

had a higher energy expenditure than the elliptical machine at three ratings o f perceived

exertion (RPE) intensities in men and women.

Maximal Oxygen Consumption (VO? max)

Bassett and Howley (2000) defined VO2 max as the “highest rate at which oxygen

can be taken up and consumed by the body during intense exercise” (p. 70). It is a

measure of aerobic fitness and health (Bassett & Howley, 2000). Various exercise modes

utilizing large muscle groups may be used to determine VO2 max, although, the treadmill

and cycle ergometer are the most common (Dalleck et al., 2004; McArdle, Katch, &

Katch, 2001). Running on a treadmill typically yields the highest VO2 max compared to

other modes, regardless of training level (Dalleck et al., 2004; McArdle et al., 2001).

Women tend to have a decreased VO2 max (5-15%) compared to men, relative to body

mass (Deschenes, Hillard, Wilson, Dubina, & Eason, 2006). Other variables resulting in

a lower VO2 max are decreased stroke volume, reduced maximal cardiac output, and

lowered hemoglobin concentration (Deschenes et al., 2006).

Heart Rate

Heart rate is used to estimate exercise intensity and prescribe exercise using a

percentage o f a person’s maximal heart rate values (Crouter, Albright, & Bassett, 2004).

There is a linear relationship between heart rate and oxygen uptake (VO2 ) when large

muscle groups are used during exercise. Heart rate and VO2 provide a rough estimate of

energy expenditure. Heart rate helps to detect changes in exercise intensity; however,

heart rate can be affected by gender, stress, training status, exercise mode, temperature,

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

and hydration level. Heart rate monitors are beneficial for people looking to improve

fitness (Crouter et al., 2004).

Rate o f Perceived Exertion

Rate of perceived exertion (RPE) is the subjective intensity o f effort, strain,

discomfort, and/or fatigue felt during exercise (Moyna, Robertson, Meckes, Peoples,

Millich, & Thompson, 2000). The 15-point Borg scale (6-20) was created for the

participant to rate his/her feelings during exercise, while accounting for environmental

conditions, personal fitness level, and fatigue (Whaley, 2006). RPE is also used to

observe maximal exertion during physical activity. When prescribing exercise to a

participant, their response to exercise should be measured via blood pressure, heart rate,

RPE, VO2 max, and electrocardiogram (ECG) when appropriate (Whaley, 2006).

Glass and Chvala (2001) administered a study on men and women to measure the

influence of exercise mode on self-selected exercise intensities. Participants (n= 12 men;

n=6 women) were between the ages o f 18 and 25. Participants performed a maximal

exercise test on a cycle ergometer and treadmill, as well as three submaximal tests on a

cycle ergometer, stair-stepper, and treadmill where they reported ratings o f preferred

exertion. Glass and Chvala (2001) found when fit and healthy men and women

completed 20-minute submaximal exercise tests at self-selected intensities on the cycle

ergometer, treadmill, and stair-stepper, the exercise intensities they chose were within the

ACSM guidelines o f 50-85% VO2 max. The cycle ergometer intensity was significantly

higher than the other two exercise modes. As the exercise bouts progressed, heart rate,

oxygen consumption, and rate o f perceived exertion (RPE) increased in a linear manner.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

The cycle ergometer mean relative VO2 was significantly higher than the treadmill and

stair-stepper; whereas the relative heart rate for the stair-stepper and cycle ergometer

were significantly higher than the treadmill. Glass and Chvala (2001) determined that

self-selected exercise intensities are similar for various exercise modes.

The energy expenditure from six exercise machines at selected intensities (RPE

11,13,15) was evaluated (Moyna, Robertson, Meckes, Peoples, Millich, & Thompson,

2000). Participants («=9 men, w=10 women) completed maximal exercise tests on six

exercise machines using the Borg scale to rate RPE: treadmill, stair-stepper, cycle

ergometer, rowing ergometer, cross-country ski simulator, and rider. Three six-minute

submaximal exercise tests were performed for each modality at an RPE of 11 (fairly

light), 13 (somewhat hard), and 15 (hard). The treadmill and ski simulator produced the

greatest energy expenditure for the men, while the treadmill, ski simulator, and rowing

ergometer resulted in the highest energy expenditure for the women. When RPE was

taken into account, the men had higher energy expenditures then the women. At all three

RPEs (11,13, and 15) there were large differences in the exercises between the men and

women. The treadmill and ski simulator were similar for men and women since they

expended the most calories on those machines (Moyna et al., 2000).

Robertson, Moyna, Sward, Millich, Goss and Thompson (2000) measured the

effect o f gender on ratings of perceived exertion (RPE) of overall body (RPE-O), legs

(RPE-L), chest (RPE-C), and arms (RPE-A). Heart rate and relative VO2 were compared

to heart rate and absolute VO2 . Participants («=9 men, «=10 women) performed six-

minute trials on a treadmill, cross-country ski simulator, and cycle ergometer while using

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

RPE to rate the intensity of exercise. Women perceived the exercise intensities to be

higher than the men for RPE-overall, RPE-legs, RPE-chest, and RPE-arms for the

submaximal absolute VO2 . When relative VO2 criteria were evaluated, there was no

difference between men and women for RPE. Robertson et al. (2000) concluded that

during 70-90% of mode specific peak values, there were no differences between RPE and

gender.

Porcari, Zedaker, Naser, & Miller (1998) compared the physiological responses of

the elliptical machine to the treadmill (run), treadmill (walk), cycle ergometer, and stair-

stepper. Participants (JV=16; n=8 men; «=8 women) performed a 20-minute exercise bout

on each exercise mode, at a self-selected intensity. Energy expenditure, VO2 , heart rate,

and rate o f perceived exertion (RPE) were recorded throughout the exercise tests. It was

found that VO2 , heart rate, and energy expenditure were not significantly different when

comparing the elliptical machine and treadmill (run); however, they were significantly

greater than the cycle ergometer, stair-stepper, and treadmill (walk). RPE was similar for

all modes of exercise. At a self-selected intensity, treadmill (run) and the elliptical

machine resulted in a larger physiologic load (Porcari et al., 1998).

Egana & Donne (2004) studied the cardiorespiratory response to exercise in semi-

sedentary women using an elliptical machine, treadmill, and stair-climber. Participants

(/V=24) were randomly assigned to one o f three exercise groups. They exercised three

times per week for 12 weeks. They worked out for 30 minutes at 70-80% o f heart rate

maximum and progressed to 40 minutes at 80-90% of heart rate maximum. Participants

performed at maximal exercise test on a cycle ergometer as well as submaximal tests.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Submaximal tests were completed during weeks 0, 4, 8, and 12 on a cycle ergometer.

From weeks 0-4 and 4-8, submaximal heart rate was significantly reduced. When

training intensity, volume, and frequency were similar (% HRmax), there were

physiologic improvements in the elliptical machine, stair-climber, and treadmill (Egana

& Donne, (2004).

Dalleck, Kravitz, and Robergs (2004) recruited recreationally active participants

(«=10 men, «=10 women) and evaluated two maximal exercise tests using the treadmill

and elliptical machine. The Balke protocol was followed during the treadmill test.

Participants were assigned instructions for the elliptical maximal test based on gender and

activity level. No significant differences were reported regarding physiological effects

between the two modes when mean VO2 max, maximal heart rate and maximal

respiratory exchange ratio were assessed. Researchers suggested that the elliptical trainer

could be used to measure maximal oxygen consumption in men and women since similar

values were recorded from the treadmill test (Dalleck et al., 2004).

Mercer, Dufek, and Bates (2001) administered a study comparing peak oxygen

consumption (VO2 ) and heart rate during treadmill and elliptical exercise tests. Fourteen

physically active college students (n=9 men, n=5 women) completed a graded exercise

test (GXT) on the treadmill and elliptical machine on separate days. There were similar

correlations in VO2 peak and peak heart rate between the treadmill and elliptical tests.

Investigators determined that the elliptical machine could be used in place of the

treadmill since there were similar results for both modes of exercise (Mercer et al., 2001).

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Kravitz, Robergs, Heyward, Wagner, & Powers (1997) evaluated VO2 and energy

expenditure after twenty minutes of self-selected submaximal exercise. Participants (n=9

men, n=9 women) completed treadmill running, simulated cross-country skiing, cycling,

and aerobic riding. Treadmill running produced a significantly higher total VO2 and

energy expenditure for men and women compared to the other modes. Men had a

significantly larger VO2 and energy expenditure, whereas women had a higher heart rate

(Kravitz et al., 1997).

Researchers compared VO2 , ventilation, heart rate, and rate of perceived exertion

(RPE) while participants exercised at self-selected intensities on various modes of

exercise (Crommett, Kravitz, Wongsathikun, & Kemerly, 1999). Participants (N= 20 men

and women) performed 6-minute randomized trials on a lower body elliptical,

upper/lower elliptical, and treadmill. There was a significant within group effect for

ventilation and heart rate. There were no differences in VO2 , however the upper/lower

elliptical trial did have an increased response to ventilation, heart rate and RPE

(Crommett et al., 1999).

Green, Crews, Pritchett, Mathfield, and Hall (2004) administered a study

comparing heart rate and ratings of perceived exertion (RPE) between the elliptical

machine and treadmill. Participants (n= 13 men, n=9 women) completed a maximal

treadmill test and two elliptical exercise tests while wearing Polar heart rate monitors.

They were directed to provide RPE according to overall exertion (RPE-Overall), leg

exertion (RPE-Legs), and breathing/chest (RPE-Chest). The first elliptical test estimated

RPE and the second test had the participants exercising progressively to their overall

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

RPE. There were no significant differences in the overall ratings o f perceived exertion

(RPE-Overall) or breathing/chest effort (RPE-Chest). When comparing heart rate

responses, there were no significant differences between the elliptical trainer and

treadmill. During elliptical exercise, participants reported a higher mean RPE for legs as

opposed to treadmill running. Investigators believed that elliptical exercise may be more

intense due to the perceived leg exertion and that RPE can regulate heart rate during

exercise (Green et al., 2004).

Batte and colleagues (2003) conducted a study measuring oxygen uptake (VO2 )

and heart rate during a maximal and submaximal exercise bout on an elliptical trainer.

On day 1, participants («=8 men; «=12 women) performed a progressive maximal

exercise test on an elliptical machine and reported their rating of perceived exertion (1-

10) at test termination. During day 2, participants completed a 15-minute submaximal

elliptical test and were instructed to build up to an RPE of six out of ten on the Borg

Scale. Heart rate and VO2 were significantly higher than the participants perceived when

using the Borg scale for ratings of perceived exertion (RPE). It was determined that

young, recreationally active participants under-estimated their perceived efforts when

performing a maximal exercise bout on an elliptical machine (Batte et al., 2003).

Twenty recreationally active, healthy participants (n=10 men, w=10 women)

performed a maximal exercise test on a cycle ergometer to volitional exhaustion and later

performed a submaximal test at 60-65% of their VO2 peak (Deschenes et al., 2006). Men

had significantly higher VO2 max values than women when comparing the maximal

exercise test, but men and women showed similar physiologic responses to the

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

submaximal test. During submaximal cycling, men recorded significantly higher systolic

blood pressure values at the 15- and 30- minute time points and also had larger plasma

volume shifts, respiratory exchange ratio values, and concentrations of plasma lactate.

Men and women exhibited similar values for heart rate, mean arterial pressure, and

temperature during exercise and recovery (Deschenes et al., 2006).

Researchers conducted a study to produce the first VO2 max prediction equation

for a submaximal elliptical exercise test (Dalleck, Kravitz & Robergs, 2006).

Participants (N= 54; n=25 men; n=29 women) completed a submaximal elliptical exercise

test and a VO2 max test 15 minutes apart. The prediction equation was derived using

stepwise multiple regression analyses and was tested by using data from the cross-

validation group. There was no significant difference between predicted and measured

VO2 max when dependent t-tests were calculated. The investigators reported that the

prediction equation and protocol could be a new way to approximate VO2 max in a non

laboratory environment (Dalleck et al., 2006).

Skinner, Gaskill, Rankinen, Leon, Rao, Wilmore, and Bouchard (2003) used the

linear relationship between oxygen uptake (VO2 ), heart rate, and exercise intensity in the

HERITAGE study to conduct a study on 653 sedentary participants. Participants

performed two maximal and one submaximal exercise tests on a cycle ergometer before

and after completing a 20-week training program. After the training program, a

significant decrease in heart rate at the same absolute power output for the total group

was seen, as was a significantly higher VO2 max for the whole group. At the same

absolute power output, women had a significantly higher heart rate. At the completion of

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

training, all three age groups exhibited a significant decrease in heart rate at the same

absolute power output. Skinner and colleagues reported that training did not affect heart

rate at a given % VO2 max in a diverse population (2003).

Investigators conducted a study measuring the accuracy of the Polar S410 heart

rate monitor for assessing energy expenditure utilizing predicted and measured heart rate

max and VO2 max on 20 participants («=10 men, «=10 women) (Crouter, Albright, &

Bassett, 2004). VO2 max and heart rate max were calculated during a maximal treadmill

test. Submaximal exercise testing was performed three times each on a cycle ergometer,

treadmill, and rowing ergometer while participants wore two watches, one predicting and

one measuring heart rate and VO2 max. Investigators reported no significant differences

for average energy expenditure regarding the predicted heart rate monitor, actual heart

rate monitor, or indirect calorimetry for any mode o f exercise. For all exercise modes,

the predicted heart rate monitor for females significantly overestimated energy

expenditure. VO2 max in men was predicted accurately, but not in women, explaining

that actual measured values need to be used. It was determined that the Polar S410 heart

rate monitor gave practical approximations of energy expenditure during three exercise

testing modes (Crouter et al., 2004).

Researchers recruited eight triathletes («=4 men, n=4 women) to participate in

maximal exercise tests using a cycle ergometer and treadmill three times throughout their

training year (Basset & Boulay, 2003). They were tested in the fall during the

preparatory training phase (phase I), in the winter during the specific training phase

(phase II), and in the summer at the start of the competitive season (phase III). Maximal

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

exercise tests were completed between two and seven days apart. Maximal heart rate was

significantly higher during the treadmill test than the cycle ergometer test during all three

phases. Relative treadmill VO2 max was significantly increased compared to the cycle

ergometer during the three testing sessions. Basset & Boulay (2003) determined that

treadmill and cycle ergometer maximal exercise tests can be used interchangeably in

athletes to evaluate training intensities.

Strath, Swartz, Bassett, O’Brien, King, and Ainsworth (2000) administered a

study examining the relationship between heart rate and VO2 during moderate intensity

field and laboratory activities. Participants (N=61) performed activities such as

vacuuming, laundry, gardening, and walking. Energy expenditure was predicted from

heart rate when age and fitness level was adjusted. Researchers found that heart rate and

VO2 during moderate intensity activities are correlated. Heart rate was a strong predictor

o f energy expenditure (Strath et al., 2000).

Investigators compared RPE-0 (overall), RPE-L (legs), and RPE-C (chest) at the

respiratory compensation threshold (RCT) on different modes of exercise (Green Crews,

Bosak, & Peveler, 2003). Participants («=18 men, «=16 women) ran on a treadmill and

rode a cycle ergometer, while estimating their RPE every minute. RPE was significantly

higher during cycling than treadmill running. RPE-L (legs) was significantly greater than

overall and chest (Green et al., 2003).

Dunbar, Goris, Michielli, and Kalinski (1994) assessed the accuracy of utilizing

ratings of perceived exertion (RPE) to regulate exercise intensity. Participants (n~9 men,

«=10 women) performed four production trials: two on a treadmill (PI A, P1B), and two

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

on a cycle ergometer (P2A, P2B). Target RPE calculated was 60% of VO2 max.

Exercise intensity was similar for PI A, PI B, and P2A, but was less for P2B. Heart rate

was also lower than the target for P2A and P2B. Investigators revealed that RPE can be

used during acute bouts o f treadmill exercise at 60% VO2 max to monitor exercise

intensity, though cycle ergometer exercise may be below the target RPE (Dunbar et al.,

1994).

Researchers evaluated participants running on a treadmill indoors and running on

an outdoor track using rate of perceived exertion (RPE), while exercising three to five

times per week (Ceci & Hassmen, 1991). Participants (n=\ 1 men) ran on an indoor

treadmill and outdoor track for 3-minute stages at an RPE 11 (light exertion), RPE 13

(somewhat hard), and RPE 15 (hard) for 5 minutes. Heart rate, blood lactate, and

velocity were significantly different for the three RPE levels. Ceci and Hassmen (1991)

found that RPE was an efficient means of measuring exercise intensity.

Glass, Knowlton, and Becque (1992) investigated the accuracy o f an exercise

intensity prescription based upon a graded exercise test (GXT) and perceptual feedback.

Participants (n=15 men) performed a GXT on a treadmill while heart rate, oxygen uptake

(VO2), and rate of perceived exertion (RPE) were measured each minute. The

participants completed a 10-minute exercise trial (EXT) 48 hours later at the prescribed

RPE on a treadmill. The GXT and EXT resulted in significant mean differences for heart

rate, although there were no significant differences for oxygen uptake. Researchers

determined that participants could use RPE to prescribe exercise intensity for a GXT on a

treadmill (Glass et al., 1992).

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Summary

There are various modes of aerobic exercise that can encourage people to be more

active, such as the elliptical machine, treadmill, and cycle ergometer. Many studies

determined that participants who exercised at self-selected intensities obtained

cardiovascular benefits and were within the American College of Sports Medicine

(ACSM) guidelines of 50-85% o f VO2 max for cardiovascular benefits. Rating of

perceived exertion (RPE) was used to rate discomfort, intensity of effort, strain and

fatigue felt during exercise. The majority of research studies indicated that the

elliptical machine and treadmill (running) resulted in the highest energy expenditure

compared to the cycle ergometer and treadmill (walking). The more energy one can

expend while exercising reduces cardiovascular disease risk and other chronic

conditions. Being more knowledgeable o f the most efficient exercise mode may

result in higher adherence to exercise programs.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

CHAPTER 3

METHODS

Participants

Twenty healthy, recreationally active men and women, between the ages of 18

and 29, participated in this randomized, two-week study. Participants were recruited

from California State University, Fullerton Kinesiology classes to volunteer for the study.

Participants read and completed medical history forms and informed consent forms

dining their first visit.

Instruments and Measurements

Participants were escorted to the Exercise Physiology Laboratory or the Lifespan

Wellness Center in the Kinesiology Department for the three exercise sessions. Exercise

testing was completed on a Monark cycle ergometer (Ergomedic 839E, Seattle, WA),

Trackmaster TM225 treadmill (Newton, KS), and Precor EFX 544 Elliptical machine

(Precor Inc., Bothel, WA), while hooked up to a rubber mouthpiece, and connected to a

Parvo Medic MMS-2400 metabolic cart (Consentius Technologies, Sandy, UT). While

exercising, participants wore a Polar heart rate monitor (Polar Inc., Westbury, NY, USA)

to record heart rate. The cycle ergometer was calibrated by hanging known weight from

the belt to make sure it measured the load correctly. Treadmills were self-calibrated for

velocity using reflective markers on the belt. The metabolic cart was calibrated for gas

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

concentrations and flow from a tank with a known gas composition using a 3-liter

calibration syringe.

Procedures

Participants came into the laboratory during the first visit for height and weight

measurements, provided their age, and were randomly assigned to an exercise order

(treadmill, elliptical machine, or cycle ergometer). They were also instructed on rating of

perceived exertion (RPE) so they could provide it during each exercise session at heart

rates of 100 bpm, 130 bpm, and 160 bpm. Participants completed all three exercise trials.

Participants were instructed to come to the laboratory hydrated by consuming 1 liter of

water the night before and 1 liter of water the morning of the exercise test. They were to

refrain from food and caffeine for at least three hours prior to the test. Participants wore

a nose-clip and rubber mouthpiece connected to a metabolic cart for gas exchange data to

be recorded and analyzed.

During the treadmill test, the participants started slowly at 1.5 mph, on a flat

incline, without holding the handrails. Every thirty seconds to one minute, the speed was

gradually increased to elicit a heart rate within five beats of the desired heart rate range

(95-105 beats per minute). They were at a steady state for three to five minutes while

oxygen uptake, energy expenditure, and RPE were recorded. For the second heart rate

range, the speed was increased every thirty seconds to within five beats of 130 bpm. If

their heart rate was not elevated enough, they were to stay at the fastest, most

comfortable walking speed (3-4 mph) and raise the incline 2-3% per minute until the

heart rate reached 130 bpm. They remained at a steady state for three to five minutes

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

while oxygen uptake, energy expenditure, and RPE were recorded. During the third heart

rate, the speed was increased to a comfortable running speed (6-7 mph) within five beats

of 160 bpm. The participants stayed at a steady state for three to five minutes for oxygen

uptake, energy expenditure, and RPE to be recorded. For the maximal test, the elevation

and speed were increased until voluntary exhaustion. Maximal oxygen uptake (VO2

max) is a measure o f cardiorespiratory fitness and is associated with the functional

capacity of the heart (Whaley, 2006).

The participants began the cycle ergometer test between 60-90 rpm and 15 W for

women and 25 W for men. The power was increased slowly in 5 W increments to within

five beats o f 100 bpm. The participants remained at a steady state for three to five

minutes while oxygen uptake, energy expenditure, and RPE were recorded. The power

was increased to 130 bpm where they stayed at a steady state for three to five minutes to

record oxygen uptake, energy expenditure, and RPE. As the participants pedaled, the

power was increased to reach a heart rate within five beats of 160 bpm. They remained at

a steady state for three to five minutes for oxygen uptake, energy expenditure, and RPE

to be recorded. There was no maximal test for the cycle ergometer.

The elliptical machine test started out slowly at 60-80 strides per minute without

arm movements, at the lowest level (1). The level was increased with slow strides to 100

bpm. Participants remained at a steady state for three to five minutes for oxygen uptake,

energy expenditure, and RPE to be recorded. The level was increased to 80-100 strides

per minute toward a heart rate o f 130 bpm. They remained at a steady state for three to

five minutes to record oxygen uptake, energy expenditure, and RPE. For the third heart

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

rate range, the level and the strides were increased to between 100-120 strides per minute

to reach 160 bpm. Participants remained at a steady state for three to five minutes for

oxygen uptake, energy expenditure, and RPE to be measured. There was no maximal test

for the elliptical machine.

Participants were instructed to cool down to below 120 bpm and scheduled a day

and time for their next exercise test, two to seven days later at the same time of day. At

the completion of the second trial, they signed up for their third exercise trial for the same

time of day. Only the principal investigator and advisor had access to the data, which

were stored securely by the principal investigator.

Design and Statistical Analysis

Data were analyzed using Statview software. Three separate 3 x 3 x 2 repeated

measures Analysis o f Variance (ANOVA) were used to evaluate the overall effect of

exercise mode at three heart rates on oxygen uptake, energy expenditure, and RPE. The

independent variables were the three exercise modes (elliptical machine, treadmill, and

cycle ergometer), three specific heart rates (100,130, and 160 bpm), and sex (male and

female). Dependent variables were oxygen uptake, energy expenditure and rate of

perceived exertion (RPE). Statistical significance was set at P < 0.05. A post-hoc

Scheffe test was implemented to isolate differences identified by the ANOVA.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

CHAPTER 4

RESULTS

Table 1 displays the descriptive statistics for age, height, weight, heart rate (HR)

peak, VO2 peak, and rate of perceived exertion (RPE) peak. Peak HR was within ten

beats of the age predicted maximum HR. Peak VO2 values using the treadmill were 38.8

ml/kg for women and 47.6 ml/kg for men, indicating a fit sample of participants. Peak

RPE was high, with the average being 19 out of 20 on the Borg scale. Table 2 shows the

results for heart rate, oxygen uptake, energy expenditure, and RPE by mode and gender.

Heart Rate

The desired heart rate at each stage was 100 bpm, 130 bpm, and 160 bpm,

respectively. Overall, it was observed that heart rate fell within 5 beats of the intended

heart rates. There was no statistical difference in heart rate at any level for the three

modes, which was expected since heart rate was controlled for. There was a significant

main effect by mode of exercise (p = .0471)

Oxygen (Of) Uptake

There was no significant difference in oxygen uptake by mode of exercise;

however, there was a significant effect by gender (p < .0001). On average, men had a

relative O2 uptake about 2 ml higher at 100 bpm, 4 ml higher at 130 bpm, and 6 ml higher

at 160 bpm.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Energy Expenditure (kcal/min)

There was no significant difference in energy expenditure between the three

modes of exercise, but there was a significant effect by gender (p < .0001). Men

exhibited energy expenditures about 1 kcal/min higher at a heart rate of 100 bpm, 3

kcal/min at 130 bpm, and 5 kcal/min at 160 bpm, compared to women.

Rate of Perceived Exertion (RPE)

There was no significant effect due to gender for RPE; however, there was a

significant main effect due to mode o f exercise (p = .0466). When the participants

exercised on the cycle ergometer, it yielded the highest RPE at all three heart rates, while

stepping on the elliptical machine resulted in the lowest RPE at heart rates of 100 bpm

and 130 bpm. When participants exercised on the elliptical machine and treadmill, the

RPE for both were significantly lower than when they pedaled on the cycle ergometer at

160 bpm. There was no difference between the elliptical machine and treadmill tests.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Table 1. Descriptive statistics of sample.

Men (N = 11) Women ( N =9)

M S D M S D

Age (y) 22.3 2.2 22.0 1.1

Height (in) 70.7 3.5 65.6 2.7

Weight (lb) 174.5 30.4 145.3 35.0

HR peak (bpm) 192.3 8.1 190.0 8.6

V 0 2 peak (ml-kg'1-min"1) 47.6 5.1 38.8 5.2

RPE peak 19.5 0.5 19.7 1.0

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Table 2. Resuits for heart rate, oxygen uptake, energy expenditure, and rate of perceived exertion (RPE) by mode and by gender.

Heart rate Men ( N = 11) W om en (N =9) Total (N = 20) (bpm) L 1 L 2 L 3 L 1 L 2 L 3 L 1 L 2 L 3

Treadmill M 100.3 132.9 163.9 99.1 132.7 163.8 99.8 132.8 163.9 SD 2.2 4 .8 6 .4 5.3 6 .3 2.6 5.4 5.4 4 .9

Cycle M 101.0 131.2 162.6 101.8 133.3 163.7 101.4 132.1 163.1 SD 2.9 2 .7 3.3 6 .7 3.5 2 .3 4 .9 3.2 2.9

Elliptical M 104.0 130.5 163.0 106.0 131.9 165.3 104.9 131.1 164.0 SD 7.8 3.3 4.4 8.7 4 .5 4 .0 8 .0 3.8 4 .3

Oxygen uptake Men (N - 11) W om en (N =9) Total ( N - 20) (ml-kg~1-min'1) L 1 L 2 L 3 L 1 L 2 L 3 L 1 L 2 L 3

Treadmill M 12.1 24.0 32.8 10.5 18.6 27.3 11.4 2 1 .6 3 0.4 SD 3.3 5.8 5.3 2.1 3.1 4 .0 2 .8 5.4 5.4

Cycle M 14.5 23.9 33.5 12.1 19.3 26.1 13.4 2 1.8 30.1 SD 2.9 4 .6 6.1 2.1 3.4 3.9 2.8 4 .6 6 .4

Elliptical M 14.3 23.1 33.5 13.0 18.5 26.6 13.7 2 1 .0 3 0.4 SD 2.5 4.8 6.4 1.4 3.9 4.7 2.1 4 .9 6 .6

Energy Men (N = 11) W om en (N -9 ) Total (N= 20) (kcal-min'1) L 1 L 2 L 3 L 1 1 2 L 3 L 1 L 2 L 3

Treadmill M 4 .6 9.1 12.7 3.4 6.1 8.9 4.1 7.8 11.0 SD 1.0 1.8 1.6 1.4 2 2 2.1 1.3 2.5 2 .6

Cycle M 5.5 9.3 13.4 3.9 6.3 8 .6 4.8 8.0 11.2 SD 0 .7 1.8 2.7 1.0 1.8 1.9 1.2 2.3 3.4

Elliptical M 5.4 9.0 13.3 4.2 6.0 8 .5 4 .9 7.6 11.2 SD 0.6 1.7 2.8 0.8 1.5 1.6 0.9 2.2 3.4

RPE Men (N = 11) W om en (N =9) Total (A/= 20)

L 1 L 2 L 3 I 1 L 2 L 3 L 1 L 2 L 3

Treadmill M 7.7 11.0 13.5 7.3 11.5 13.7 7.4 10.9 13.6 SD 2.0 2.1 2.3 1.1 1.1 1.4 1.6 1.7 1.9

Cycle M 7.8 11.2 15.6 7.7 11.6 14.6 7.8 11.4 15.2 SD 1.9 2.8 2.3 1.6 1.7 1.4 1.7 2 .3 2 .0

Elliptical M 7 .0 10.8 14.4 7.2 9.3 12.8 7.1 10.1 13.7 SD 1.3 1.8 1.8 1.7 2.3 1.1 1.4 2 .0 1.7

Note: L 1 = desired HR of 100 bpm; L 2 = desired HR of 130 bpm; L 3 = desired HR of 160 bpm.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

CHAPTER 5

DISCUSSION

The purpose of the study was to compare the energy expenditure, oxygen uptake,

and the rate of perceived exertion (RPE) of various modes of exercise (treadmill,

elliptical machine, and cycle ergometer) at three specified heart rates (100 bpm, 130 bpm,

and 160 bpm). It was determined that the participants in this study could get the same

oxygen uptake and energy expenditure at a lower rate of perceived exertion (RPE) when

using the elliptical machine and the treadmill at all three heart rates. When compared to

the cycle ergometer, either the elliptical machine or treadmill would be preferred for a

person to lose weight, because they expend more energy at the same or lower RPE due to

incorporating more muscle mass. The cycle ergometer yielded a higher RPE at all three

heart rates (100 bpm, 130 bpm, and 160 bpm).

The energy expenditure was greater in men for all levels and modes of exercise,

which is in agreement with other studies. Cook et al. (2004) found that when comparing

the treadmill and elliptical machines at self-selected intensities, men used more total

energy than women. When performing submaximal exercise tests on the treadmill, stair-

stepper, cycle ergometer, rowing ergometer, ski simulator, and aerobic rider at RPEs of

11,13, and 15, men on average had 50% greater energy expenditure on all exercise

modalities compared to the women (Moyna et al., 2000). The current study demonstrates

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

energy expenditure for men is 40% higher than women. When comparing twenty

minutes of self-selected exercise on the treadmill, cross country ski simulator, aerobic

rider, and cycle ergometer, men had significantly greater energy expenditure than women

(Kravitz et al., 1997). At each o f the three intended ranges, heart rate was 30 beats higher

for the three modes, which led to an energy expenditure increase of 3 kcal/min. On

average for a 10-beat increase in heart rate, there was an increase in energy expenditure

of about 1 kcal/min regardless of exercise mode.

Oxygen uptake in men was 25-30% greater than women at all three heart rates

(100 bpm, 130 bpm, and 160 bpm), which is in agreement with other studies. When

comparing four modes o f self-selected submaximal exercise, men had significantly

higher oxygen uptake levels (25-30% higher) than women (Kravitz et al., 1997). Moyna

and colleagues (2000) determined that maximum oxygen uptake was 10-20% higher in

men than women on each exercise modality. This result is most likely due to men having

less body fat compared to women (Moyna et al., 2000). Men have greater body mass,

lean tissue mass, VO2 max, lower relative body fat, and are taller than women (Green et

al., 2003).

There was a difference in RPE based on the mode of exercise. Participants

reported lower RPE values at the same heart rate when exercising on the elliptical

machine and treadmill, compared to the cycle ergometer. The higher RPE values may be

due to participants being unfamiliar with the cycle ergometer, less muscle mass involved,

and localized muscle fatigue. Green et al. (2003) found that cycling had a significantly

higher RPE compared to the treadmill, specifically, RPE-legs was significantly greater

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

than RPE-overall and RPE-chest. Batte and colleagues (2003) determined that when

participants exercised on the elliptical machine at an intensity of six out of ten on the

Borg Scale that their heart rate and oxygen uptake were significantly greater than what

they perceived. Green et al. (2004) compared RPE between the treadmill and elliptical

machine. They found during the elliptical exercise that RPE-legs was significantly

greater compared to the treadmill.

In addition to quantitative data, the participants completed a questionnaire asking

them to rank each exercise mode on a scale of one to 10, explain what they liked and

disliked about each mode, and which mode they preferred and why. The majority (9/20)

preferred the elliptical machine, followed by the treadmill (7/20), and cycle ergometer

(4/20). Many of the participants who preferred the elliptical machine said they liked that

they could work at a lower perceived intensity and raise their heart rate easily. They also

liked that the elliptical machine was low impact and did not hurt their knees. The

participants who preferred the treadmill exercise enjoyed running and pushing themselves

to a higher RPE. Of those who preferred the cycle ergometer, they liked the increased

resistance and enjoyed strengthening their lower body. All o f the participants reported

discomfort with the cycle ergometer seat and disliked the mouthpiece, which measured

oxygen consumption in all three exercise modes.

When applying the results of this study in a fitness setting, the treadmill and

elliptical machine elicit the same RPE, oxygen uptake, and energy expenditure, at the

same or lower heart rate than the cycle ergometer. The elliptical machine and treadmill

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

are recommended for fitness improvements and weight loss when participants self-select

an exercise intensity.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

APPENDIX A

California State University, Fullerton (CSUF) CONSENT TO ACT AS A HUMAN RESEARCH SUBJECT

Comparing the Energy Expenditure and Rating of Perceived Exertion of Various Exercise Modes at Specified Heart Rates

Participation in this research study is completely voluntary. Please read this information below and ask questions about anything that you do not understand before deciding if you want to participate. A researcher listed below will be available to answer your questions.

INVESTIGATORS AND SPONSOR Lead Researcher

• Julie Smith - Department o f Kinesiology

Study Location(s):

• Cal State University, Fullerton

Study Sponsor(s):

• William Beam, Ph.D. - Department of Kinesiology

PURPOSE OF STUDY The purpose of the study is to compare the energy (calories) expended and the rate of perceived exertion (RPE) of various modes of exercise (treadmill, elliptical machine, and cycle ergometer) at three specified heart rates (100,130, and 160 bpm). There is no conclusive research comparing energy expenditure and RPE of these three exercise modes. If people were more aware of the most efficient exercise mode resulting in the highest energy expenditure, they may be more inclined to exercise and adhere to an appropriate exercise program.

WHY THIS IS A RESEARCH STUDY

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

We want to know if there is a difference in the energy expended and in the perceived effort of participants between three different exercise modes (elliptical machine, treadmill, and cycle ergometer) at three heart rates (100,130, and 160 bpm). We want to know what mode of exercise will expend the most energy (calories) with the feeling of least exertion at each of the three heart rates. Participants will exercise on all three modes of exercise in random order.

PARTICIPANTS

Inclusion Criteria: Participants in this study will be apparently healthy men and women, between the ages of 18 and 29, who are at a low risk for heart disease according to the American College of Sports Medicine. They will be recreationally active, defined as participating in aerobic exercise two or more times per week in the past three months. Participants will be recruited from California State University, Fullerton to volunteer in the study. Low risk is defined as men under the age of 45 and women under the age of 55, who are asymptomatic and have no more than one major risk factor for cardiovascular disease (Whaley, 2006). Major risk factors include: 1) Family history o f myocardial infarction, coronary revascularization, sudden death

before the age o f 55 years in a father or other male first degree relative, or before 65 years of age in a mother or other female first-degree relative.

2) Current cigarette smoker or has quit in the previous 6 months. 3) Hypertension with a systolic blood pressure of > 140 mm Hg or a diastolic blood

pressure o f > 90 mm Hg. 4) Dyslipidemia: Low-density lipoprotein (LDL) cholesterol >130 mg/dL or high

density lipoprotein (HDL) cholesterol < 40 mg/dL, or on lipid-lowering medication, or if total serum cholesterol is > 200 mg/dL.

5) Impaired fasting glucose: Fasting blood glucose >100 mg/dL. 6) Obesity: Body mass index > 30 kg/m, or waist girth >102 cm. for men and > 88 cm

for women, or waist to hip ratio > 0.95 for men and > 0.86 for women. 7) Sedentary lifestyle: Not participating in regular exercise or not meeting the minimal

physical activity recommendations from the U.S. Surgeon General’s Report.

Exclusion Criteria: Anyone who does not fit the inclusion criteria will be excluded - specifically anyone outside the age range (18-29 y), or anyone who does not qualify as low risk by ACSM definition.

Number o f participants: The investigator plans to enroll 30 participants at this site.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

PROCEDURES

• Preliminary Testing - Participants will read and complete medical history forms and consent forms. They will be randomly assigned to an exercise order. Participants will schedule a day and time for their exercise tests.

• Testing - The day of the exercise test, participants will come into the lab hydrated by drinking 1 liter o f water the night before and drinking 1 liter of water the morning of the test. They must refrain from food or caffeine at least 3 hours prior to the exercise test. Participants will be measured for height and weight and provide their age. They will be instructed on rating o f perceived exertion (RPE) in order to report their RPE during the exercise session at heart rates o f 100,130, and 160 bpm. Participants will wear a heart rate monitor and will be connected via a rubber mouthpiece to a metabolic cart for gas exchange data to be recorded and analyzed.

• For the treadmill test, the participants will start stage 1 (-100 bpm) slowly on a flat incline walking at 1.5 mph, without using the handrails. Depending on how slow or fast their heart rate elevates, the speed will increase every 30 sec to 1 min. They will gradually increase speed to within 5 beats of the desired heart rate range (95-105 bpm). Participants will remain at a steady state for 3 to 5 minutes while energy expenditure and RPE are recorded. From there, the participant will begin stage 2 (-130 bpm) by increasing the speed every 30 seconds to within 5 beats of 130 bpm. If heart rate is not elevated enough, participants will stay at their fastest, most comfortable walking speed (3-4 mph) and raise the incline 2-3% per minute. They will stay at a steady state for 3 to 5 minutes while energy expenditure and RPE are recorded. During stage 3 (-160 bpm) the speed will be increased to a comfortable running speed (5-7 mph) to within 5 beats of 160 bpm. The participants will stay at a steady state 3 to 5 minutes while energy expenditure and RPE are recorded. Following stage 3, each participant will complete a maximal exercise test through a continual increase in speed and grade until voluntary exhaustion.

• Participants will begin stage 1 (-100 bpm) o f the cycle ergometer test at 60-90 rpm and 15 Watts (W) for women and 25 W for men. The power will be increased slowly in 5 W increments to within 5 beats o f 100 bpm and they will remain at a steady state for 3 to 5 minutes for energy expenditure and RPE to be recorded. During stage 2 (-130 bpm) power will be increased slowly in 5 W increments until heart rate is within 5 beats of 130 bpm and stay at a steady state for 3 to 5 minutes to record energy expenditure and RPE. During stage 3 (-160 bpm) power will be increased slowly in 5 W increments until heart rate is within 5 beats of 160 bpm and stay at a steady state for 3 to 5 minutes to record energy expenditure and RPE. Following stage 3, each participant will complete a maximal exercise test through a continual increase in power until voluntary exhaustion.

• The elliptical test will begin with stage 1 (—100 bpm). The participant exercises slowly at 60-80 strides/min without arm movement, at the lowest level (level 1). Participants will increase the level until heart rate is within 5 beats o f 100 bpm and will stay at a steady state 3 to 5 minutes to record energy expenditure and RPE. During stage 2 (-130 bpm) the level will be increased to 80-100 strides/minute to

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

reach 130 bpm. They will remain at a steady state for 3 to 5 minutes to record the energy expenditure and RPE. For stage 3 (-160 bpm) there will be an increase in level and strides to 100-120 strides/minute to reach 160 bpm. Participants will remain at a steady state for 3 to 5 minutes to record energy expenditure and RPE. Following stage 3, each participant will complete a maximal exercise test through a continual increase in stride rate and level until voluntary exhaustion.

• Participants will be instructed to warm down and schedule a day and time for their next exercise test, 2 to 7 days later at the same time of day. At the completion of the second trial, they will sign up for their third exercise trial. Only the principle investigator and advisor will have access to the data, which will be stored securely by the principle investigator.

Total Time Involved: You will be involved in this study for approximately 2 weeks. You will need to come into the lab 3 times for each exercise test for approximately 60 minutes each time. Each exercise session will be separated by two to seven days.

RISKS Risk of Testing

• Less Likely/Serious - Shortness of breath • Less Likely/Serious - Light headedness • Likely/Not Serious - Sweating • Less Likely/Very Serious - Cardiovascular events • Less Likely/Very Serious - Death

Risks fo r Other Procedures

• Exercise testing - The exercise test may cause muscle soreness, dizziness, or shortness of breath. In rare instances, exercise tests may cause chest pain, tightness, or a change in vital signs.

BENEFITS To the Participant You will benefit directly from this study by learning about the number of calories you expend on different exercise machines and the rate of perceived exertion for those exercises at three different heart rates. Exercise testing is free to participants in this study.

ALTERNATIVES TO PARTICIPATION The alternative is to not participate in this study.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

COMPENSATION/COST/REIMBURSEMENT You will not be required to pay for research related procedures/treatments.

COMPENSATION FOR INJURY I understand that if I am injured as a result o f my participation in this study, I will be provided reasonable and necessary medical care to treat the illness or injury at no cost to me or to my insurer/third party payer. CSU Fullerton does not provide any other form of compensation for injury. I understand that I must report any suspected study-related illness or injury to the study investigator immediately.

WITHDRAWAL OR TERMINATION FROM STUDY You are free to withdraw from the study at any time. If you decide to withdraw from the study, you should inform the researchers immediately. You may also be removed from the study without your consent because of the following: A) based on the researcher's judgment to improve your health and welfare, or B) because you have not followed the study procedures.

CONFIDENTIALITY Data Storage Your research records including computer-based data or other identifying information will be stored in a secured building and on a password protected computer. Your data may be used for future research that may be published. Data Access The research team, authorized CSUF personnel, and regulatory entities may have access to your study records to protect your safety and welfare. Data will be kept confidential to the extent allowed by law. Data will be reported without identifiers.

Level o f Privacy

• To protect your privacy and the confidentiality of the data, all personal identifiers will be removed from the data records and a code will be used in place of your name.

Data Privacy

• The research data will be maintained indefinitely.

NEW FINDINGS If during the course o f this study, significant new information becomes available that may

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

relate to your willingness to continue to participate, this information will be provided to you by the investigator

IF I HAVE QUESTIONS For questions about your rights as a research participant, you may contact California State University, Fullerton Regulatory Compliance Coordinator at (714) 278-2327, or the Institutional Review Board (IRB) Chair at (714) 278-2141

Contacts:

• Dr. William Beam Daytime Phone: (714) 278-3432 Email: [email protected]

• Julie Smith, Department of Kinesiology Daytime Phone: (714) 854-7347 Email: [email protected]

. VOLUNTARY PARTICIPATION I have read the attached "Experimental Subject's Bill o f Rights" and have been given a copy of it and this consent form to keep. I understand that participation in this study is voluntary. I may refuse to answer any question or discontinue my involvement at any time without penalty or loss of benefits to which I might otherwise be entitled. My decision will not affect my future relationship with or the quality of care I receive at CSU Fullerton. My signature below indicates that I have read the information in this consent form and have had a chance to ask any questions I have about the study. I consent to participate.

Signature of Participant Date

Signature of Witness Date

Signature of Investigator Date

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

APPENDIX B

Medical History Questionnaire

Name ________________________________________ Gender Age ______

E-mail Address

Phone

Please provide the following information as accurately and completely as possible so that your risk of exercise may be assessed.

Known Cardiovascular, Pulmonary or Metabolic Disease Have you been diagnosed with any of the following diseases/disorders/conditions or had any of the following procedures? □ Yes □ No Myocardial infarction (“heart attack”) 1 □ Yes □ No Stroke or ischemic attack (“mini-stroke”) 2 □ Yes □ No Heart bypass surgery or other heart surgery 3 □ Yes □ No Coronary catheterization and/or angioplasty 4 □ Yes □ No Abnormal ECG (tachycardias, heart blocks, etc.) 5 □ Yes □ No Other cardiovascular disease/disorder (aneurysm, etc.) 6 □ Yes □ No Chronic obstructive pulmonary disease (COPD, etc.) 7 □ Yes □ No Diabetes (insulin dependent, non-insulin dependent, etc.) s □ Yes □ No Hyperlipidemia (high LDL, low HDL, etc.) 9 Comment:

Signs or Symptoms Suggestive of Cardiovascular and Pulmonary Disease

Have you experienced any of the following? □ Yes □ No Pain/discomfort in your chest, jaw or arms 10 □ Yes □ No Shortness of breath at rest or mild exertion 11 □ Yes □ No Dizziness or fainting spells 12 □ Yes □ No Difficulty breathing while lying down 13 n Yes □ No Swelling of your ankles 14

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

□ Yes □ No “Skipped” heart beats or a “racing” heart beat 15 □ Yes □ No Occasional leg pain, especially while walking 16 □ Yes □ No Heart murmur n □ Yes □ No Fatigue or shortness of breath with usual activities is Comment:

Risk Factors o f Cardiovascular Disease Do you have a personal history of any of the following? □ Yes □ No Cigarette smoking 19 Packs/day____ ,yrs smoked □ Yes □ No Obesity or highly overweight 20 □ Yes □ No Physical inactivity 21 □ Yes □ No High blood pressure (over 140/90 mmHg) 22 Blood pressure □ Yes □ No High cholesterol (over 200 mg/dl) 23 Cholesterol _____

Yes □ No Diabetes or high blood sugar (over 110 mg/dl) 24 Blood glucose

□ Yes □ No Family history of heart attack/stroke, at young age 25 Comment:

Other Information Concerning Personal Health History List anything else concerning your personal health history. Comment:

Physical Activity Readiness Questionnaire (PAR-Q) Has your doctor ever said you have a heart condition and should only do physical activity recommended by a doctor? 26 Do you feel pain in your chest when you do physical activity? 27 In the past month, have you had chest pain when you were not physically activity? 28 Do you lose your balance because of dizziness or do you ever lose consciousness? 29 Do you have a bone or joint problem that could be made worse by a change in your physical activity? 30 Is your doctor currently prescribing drugs for your blood pressure or heart condition? 31 Do you know of any other reason why you should not do physical

□ Yes □ No

□ Yes □ No a Yes □ No

□ Yes □ No

□ Yes □ No activity? 32 Comment:

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Medications

Please list any prescription or over the counter (OTC) medications you are currently taking.

In Case of Emergency Name

Phone

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

APPENDIX C

QUESTIONNAIRE

Comparing the Energy Expenditure and Rating of Perceived Exertion of Various Exercise Modes at Specified Heart Rates

Principal Investigator: Julie Smith

Thank you for participating in my study. Please take a moment to answer the following questions.

1. Please rank your experience with each exercise test on a scale of 1-10:

Treadmill:

Cycle Ergometer:

Elliptical Machine:

2. Please explain what you liked and disliked about each exercise test:

Treadmill:

Cycle Ergometer:

Elliptical Machine:

3. What exercise test did you prefer and why? Please be as detailed as possible.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

APPENDIX D

Appointment Reminder for Exercise Testing

Test Date Time

1. The testing is done in KHS-014 or the Lifespan Wellness Center (basement of KHS building).

2. Please come into the lab hydrated by drinking 1 Liter of water the night before the test and drinking 1 Liter of water the morning of the test.

3. You must be fasted before the test; no food except for water 3 hours prior to the test.

4. Do not have any caffeine (coffee, Cola, Red Bull, NoDoz, etc.) at least 3 hours prior to the test.

5. Do not smoke cigarettes within 3 hours o f the test. 6. Take prescription drugs as normal. Bring your inhaler if you are asthmatic. 7. Do not take non-prescription drugs or consume alcohol the day o f the test. 8. Please wear a t-shirt, shorts, and running shoes. 9. Please be on time for your appointment. You should only miss because of illness

or emergency. Please call if you cannot make your appointment.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

APPENDIX E

Rate o f Perceived Exertion (RPE) INSTRUCTIONS

20 Very very hard (heavy)

18 Very hard (heavy)

16 Hard (heavy)

14 Somewhat hard (heavy)

12 Fairly easy (light)

10 Very easy (light)

8 Very, very easy (light)

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

REFERENCES

Basset, F. A., & Boulay, M. R. (2003). Treadmill and cycle ergometer tests are

interchangeable to monitor triathletes’ annual training. Journal o f Sports Science

& Medicine, 2, 110-116.

Bassett, D. R. & Howley, E. T. (2000). Limiting factors for maximum oxygen uptake

and determinants of endurance performance. Medicine & Science in Sports &

Exercise, 32, 70-84

Batte, A. L., Darling, J., Evans, J., Lance, L. M., Olson, E. I., & Pincivero, D. M. (2003).

Physiologic response to a prescribed rating o f perceived exertion on an elliptical

fitness cross-trainer. Journal o f Sports Medicine and Physical Fitness, 43, 300-

305.

Carter, H., Jones, A. M., Barstow, T. J., Burnley, M., Williams, C. A., & Doust, J. H.

(2000). Oxygen uptake kinetics in treadmill running and cycle ergometry: a

comparison. Journal o f Applied Physiology, 89, 899-907.

Ceci, R., & Hassmen, P. (1991). Self-monitored exercise at three different rpe intensities

in treadmill vs. field running. Medicine & Science in Sports & Exercise, 6, 732-

738.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Cook, C., Heelan, K. A., & Kruegar, R. (2004). Comparison of energy expenditure on

the treadmill vs. the elliptical machine at a self-selected intensity. Medicine &

Science in Sports & Exercise, 36, S249.

Crommett, A., Kravitz, L., Wongsathikun, J., & Kemerly, T. (1999). Comparison of

metabolic and subjective response of three modalities in college-age subjects.

Medicine & Science in Sports & Exercise, 31, S I58.

Crouter, S. E., Albright, C., & Bassett, D. R. Jr. (2004). Accuracy of polar s410 heart rate

monitor to estimate energy cost of exercise. Medicine & Science in Sports &

Exercise, 36, 1433-1439.

Dalleck, L. C., Kravitz, L., & Robergs, R. A. (2006). Development of a submaximal test

to predict elliptical cross-trainer V02max. Journal o f Strength and Conditioning

Research, 20, 278-283.

Dalleck, L. C., Kravitz, L., & Robergs, R., A. (2004, June). Maximal exercise testing

using the elliptical cross-trainer and treadmill. Journal o f Exercise Physiology

Online, 7, ISSN 1097-9751. Retrieved August 28, 2006, from

www.jeponline.com.

Deschenes, M. R., Hillard, M. N., Wilson, J. A., Dubina, M. I., & Eason, M. K. (2006).

Effects of gender on physiological responses during submaximal exercise and

recovery. Medicine & Science in Sports & Exercise, 38, 1304-1310.

Dugas, L. R., Van Der Merwe, L., Odendaal, H., Noakes, T. D., & Lambert, E. V. (2005).

A novel energy expenditure prediction equation for intermittent physical activity.

Medicine & Science in Sports & Exercise, 37, 2154-2161.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Dunbar, C. C., Goris, C., Michielli, D. W., & Kalinski, M. I. (1994). Accuracy and

reproducibility of an exercise prescription based on ratings o f perceived exertion

for treadmill and cycle ergometer exercise. Perceptual and Motor Skills, 78,

1335-1344.

Egana, M., & Donne, B. (2004). Physiological changes following a 12 week gym based

stair-climbing, elliptical trainer and treadmill running program in females.

Journal o f Sports Medicine and Physical Fitness, 44, 141-146.

Glass, S. C., & Chvala, A. M. (2001). Preferred exertion across three common modes of

exercise training. Journal o f Strength and Conditioning Research, 15, 474-479.

irlass, S. C., Knowlton, R. G., & Becque, M. D. (1992). Accuracy of rpe from graded

exercise to establish exercise training intensity. Medicine & Science in Sports &

Exercise, 24, 1303-1307.

Green, J. M., Crews, T. R., Bosak, A. M., & Peveler W. W. (2003). Overall and

differentiated ratings of perceived exertion at the respiratory compensation

threshold: effects of gender and mode. European Journal o f Applied Physiology,

89, 445-450.

Green, J. M., Crews, T. R., Pritchett, R. C., Mathfield, C., & Hall, L. (2004). Heart rate

and ratings of perceived exertion during treadmill and elliptical exercise training.

Perceptual and Motor Skills, 98, 340-348.

Kravitz, L., Robergs, R. A., Heyward, V. H., Wagner, D. R., & Powers, K. (1997).

Exercise mode and gender comparisons of energy expenditure at self-selected

intensities. Medicine & Science in Sports & Exercise, 2 9 ,1028-1035.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Kravitz, L., & Vella, C. A. (2002, June). Energy expenditure in different modes of

exercise. American College o f Sports Medicine, Current Comment.

www.acsm.org.

Loftin, M., Sothem, M., Warren, B., & Udall, J. (2004). Comparison o f VO2 peak during

treadmill and cycle ergometry in severely overweight youth. Journal o f Sports

Science & Medicine, 3, 254-260.

McArdle, W. D., Katch, F. I., & Katch, V. L. (2001). Exercise physiology: Energy,

nutrition, and human performance 5th ed. Baltimore: Lippincott Williams &

Wilkins.

Mercer, J. A., Dufek, J. S., & Bates, B. T. (2001). Analysis o f peak oxygen consumption

and heart rate during elliptical and treadmill exercise. Journal o f Sport

Rehabilitation, 10, 48-56.

Moyna, N. M., Robertson, R. J., Meckes, C. L., Peoples, J. A., Millich, N. B., &

Thompson, P. D. (2000). Intermodal comparison of energy expenditure at

exercise intensities corresponding to the perceptual preference range. Medicine &

Science in Sports & Exercise, 33, 1404-1410.

Paton, C. D. & Hopkins, W. G. (2001). Tests o f cycling performance. Sports Medicine,

31, 489-496.

Porcari, J. P., Zedaker, J. M., Naser, L., & Miller, M. (1998). Evaluation of an elliptical

exerciser in comparison to treadmill walking and running, stationary cycling and

stepping. Medicine & Science in Sports & Exercise, 30, sl68.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Robertson, R. J., Moyna, N. M., Sward, K. L., Millich, N. B., Goss, F. L., & Thompson,

P. D. (2000). Gender comparison of rpe at absolute and relative physiological

criteria. Medicine & Science in Sports & Exercise, 32, 2120-2129.

Sanders, L. F., & Duncan, G. E. (2006). Population-based reference standards for

cardiovascular fitness among u.s. adults: nhanes 1999-2000 and 2001-2002.

Medicine & Science in Sports & Exercise, 38, 701-707.

Skinner, J. S., Gaskill, S. E., Rankinen, T., Leon, A. S., Rao, D. C., Wilmore, J. H., &

Bouchard, C. (2003). Heart rate versus % VO2 max: age, sex, race, initial fitness,

and training response-heritage. Medicine & Science in Sports & Exercise, 35,

1908-1913.

Strath, S. J., Swartz, A. M., Bassett, D. R., O’Brien, W. L., King, G. A., & Ainsworth, B.

E. (2000). Evaluation of heart rate as a method for assessing moderate intensity

physical activity. Medicine & Science in Sports & Exercise, 32, S465-S470.

Thomas, C. L. (Ed.). (1997). Taber’s cyclopedic medical dictionary (18th ed.).

Philadelphia: F.A. Davis Company.

U.S. Department of Health and Human Services. (2006). A report from the surgeon

general: Physical activity and health. Atlanta, GA.

Vella, C. A., & Robergs, R. A. (2005). Non-linear relationships between central

cardiovascular variables and VO2 during incremental cycling exercise in

endurance-trained individuals. Journal o f Sports Medicine and Physical Fitness,

45, 452-459.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

Wallace, B. P., Sforzo, G., & Swensen, T. (2004). Energy expenditure: Elliptical v.

treadmill exercise at selected rpe. Medicine & Science in Sports & Exercise, 36,

S249.

Whaley, M. H. (Ed.). (2006). ACSM’s guidelines for exercise testing and prescription

(7th ed.). Philadelphia: Lippincott Williams & Wilkins.

World Health Organization. (October 19,2006). One billion people overweight, 300

million obese worldwide. Retrieved October 20, 2006, from

http://www.breitbart.com/news/2006.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.