Exercise and Appetite: The Influence of Exercise Intensity on Appetite in Endurance Trained Women

134 Pages·2015·1.58 MB·English

AN
 ABSTRACT
 OF
 THE
 DISSERTATION
 OF

Stephanie
 M.
 Howe
 for
 the
 degree
 of
 Doctor
 of
 Philosophy
 in
 Exercise
 and
 Sport
 Science

presented
 on
 December
 11th,
 2015.

Title:
 Exercise
 and
 Appetite:
 The
 Influence
 of
 Exercise
 Intensity
 on
 Appetite
 in
 Endurance

Trained
 Women.

Abstract
 approved:

Melinda
 M.
 Manore

In
 endurance-­‐trained
 men,
 an
 acute
 bout
 of
 exercise
 is
 shown
 to
 suppress
 post-­‐exercise

appetite
 and
 alter
 changes
 in
 specific
 appetite
 regulating
 hormones.
 Limited
 research
 has

examined
 these
 responses
 in
 endurance-­‐trained
 women.
 PURPOSE:
 To
 investigate
 the

effect
 of
 exercise
 intensity
 on
 the
 appetite
 regulating
 hormones
 acylated
 ghrelin,
 PYY
 and

GLP-­‐1
 and
 subjective
 ratings
 of
 appetite
 in
 endurance
 trained
 women.
 METHODS:

 Fifteen

highly-­‐trained
 women
 (18-­‐40y,
 58.4±6.4kg,
 VO =55.2±4.3
 mL/kg/min)
 completed

2MAX
isocaloric
 bouts
 of
 moderate
 intensity
 exercise
 (MIE)
 at
 60%VO ,
 and
 2)
 and
 high-­‐
2MAX
intensity
 exercise
 (HIE)
 at
 85%VO in
 randomly
 assigned
 order.
 In
 both
 trials,
 subjects

2MAX

ran
 on
 a
 treadmill
 until
 an
 energy
 expenditure
 (EE)
 of
 500
 kcal
 was
 achieved.
 Blood
 was

drawn
 pre-­‐exercise
 (baseline),
 immediately
 post-­‐exercise
 and
 every
 20-­‐min
 for
 the
 next

60-­‐min.
 Plasma
 concentrations
 of
 acylated
 ghrelin,
 PYY ,
 GLP-­‐1
 and
 subjective
 appetite

3-­‐36
ratings
 via
 visual
 analog
 scale
 (VAS)
 were
 assessed
 at
 these
 same
 time
 points.
 Food
 intake

and
 physical
 activity
 were
 recorded
 48-­‐h
 before
 each
 trial.
 A
 mixed
 model
 analysis
 was

used
 to
 examine
 the
 impact
 of
 exercise
 intensity
 (60%
 vs.
 85%
 VO max)
 on
 appetite-­‐
2
regulatory
 hormones
 and
 VAS
 responses
 over
 time.
 Where
 significant
 effects
 were
 found,

post-­‐hoc
 analyses
 were
 performed
 using
 the
 Bonferroni
 correction
 for
 multiple

comparisons.
 For
 these
 same
 variables
 area
 under
 the
 curve
 (AUC)
 was
 calculated
 using

the
 trapezoid
 method
 to
 determine
 total
 response
 over
 time.
 The
 overall
 statistical

significance
 was
 accepted
 at
 the
 5%
 level.
 RESULTS:
 Results
 for
 appetite
 hormones

showed
 no
 main
 effect
 for
 exercise
 intensity
 or
 interactive
 effects,
 but
 a
 significant
 main

effect
 for
 time;
 thus,
 data
 were
 combined
 across
 exercise
 intensities
 for
 each
 time
 point.

Acylated
 ghrelin
 decreased
 (p=0.014)
 and
 PYY
 and
 GLP-­‐1
 increased
 (p=0.036,

3-­‐36
p<0.0001)
 immediately
 post-­‐exercise
 compared
 to
 pre-­‐exercise,
 indicating
 appetite

suppression.
 Examination
 of
 AUC
 showed
 no
 differences
 between
 exercise
 intensities
 for

acylated
 ghrelin
 (p=0.055)
 and
 PYY
 (p=0.54).
 For
 GLP-­‐1,
 AUC
 was
 slightly
 higher
 in
 the
 MIE

compared
 to
 the
 HIE
 trial
 (p=0.04,
 uncorrected).
 Results
 for
 appetite
 ratings
 were
 similar,

with
 no
 differences
 in
 AUC
 between
 MIE
 and
 HIE
 trials
 for
 ratings
 of
 hunger,
 satisfied,
 and

desire
 to
 eat.
 There
 was
 a
 trend
 for
 AUC
 ratings
 of
 fullness
 to
 be
 lower
 after
 the
 HIE

compared
 to
 the
 MIE
 (p=0.03,
 uncorrected).
 For
 appetite
 ratings,
 there
 was
 a
 significant

main
 effect
 for
 time,
 with
 no
 interactive
 effects.

 Hunger
 and
 desire
 to
 eat
 decreased

immediately
 post-­‐exercise
 (p=0.0012,
 p=0.0031,
 respectively)
 compared
 to
 baseline,
 and

desire
 to
 eat
 was
 also
 higher
 (p=0.0031)
 60-­‐min
 post-­‐exercise.

 Satisfied
 and
 Fullness

increased
 (p=0.0005,
 p=0.0006,
 respectively)
 at
 60-­‐min
 post-­‐exercise.

 CONCLUSION:

Similar
 to
 males,
 post-­‐exercise
 appetite
 regulatory
 hormones
 were
 altered
 toward

suppression
 in
 highly
 trained
 women.
 Based
 on
 AUC
 data,
 HIE
 suppressed
 feelings
 of

fullness
 compared
 to
 MIE,
 but
 did
 not
 impact
 post-­‐exercise
 hormone
 response
 or
 other

ratings
 of
 appetite.
 Since
 EE
 was
 held
 constant
 between
 MIE
 and
 HIE
 trials,
 these
 findings

were
 independent
 of
 the
 energy
 cost
 of
 exercise.

 Thus,
 in
 highly-­‐trained
 women,
 post-­‐
exercise
 appetite
 suppression
 was
 similar
 regardless
 of
 exercise
 intensity.

 For
 female

athletes
 trying
 to
 optimize
 nutrition
 for
 endurance
 performance,
 post-­‐exercise
 appetite

suppression
 could
 alter
 the
 amount,
 type
 and
 the
 timing
 of
 food
 intake.
 These
 possible

changes
 in
 post-­‐exercise
 appetite
 need
 to
 be
 considered
 in
 the
 overall
 nutrition
 strategies

recommended
 to
 active
 women
 to
 support
 athletic
 performance.
©Copyright
 by
 Stephanie
 M.
 Howe

December
 11th,
 2015

All
 Rights
 Reserved
Exercise
 and
 Appetite:
 The
 Influence
 of
 Exercise
 Intensity
 on
 Appetite
 in
 Endurance

Trained
 Women

by

Stephanie
 M.
 Howe

A
 DISSERTATION

Submitted
 to

Oregon
 State
 University

in
 partial
 fulfillment
 of

the
 requirements
 for
 the

degree
 of

Doctor
 of
 Philosophy

Presented
 December
 11th,
 2015

Commencement
 June
 2016
Doctor
 of
 Philosophy
 dissertation
 of
 Stephanie
 M.
 Howe
 presented
 on
 December
 11,
 2015.

APPROVED:

Major
 Professor,
 representing
 Exercise
 and
 Sport
 Science

Co-­‐Director
 of
 the
 School
 of
 Biological
 and
 Population
 Health
 Sciences

Dean
 of
 the
 Graduate
 School

I
 understand
 that
 my
 dissertation
 will
 become
 part
 of
 the
 permanent
 collection
 of
 Oregon

State
 University
 libraries.
 My
 signature
 below
 authorizes
 release
 of
 my
 dissertation
 to
 any

reader
 upon
 request.

Stephanie
 M.
 Howe,
 Author
ACKNOWLEDGEMENTS

This
 dissertation
 would
 not
 have
 been
 possible
 without
 the
 support
 of
 my
 advisor

and
 mentor,
 Dr.
 Melinda
 Manore.

 Thank
 you
 so
 much
 for
 believing
 in
 me
 and
 supporting

me
 through
 this
 entire
 process.
 I
 have
 learned
 so
 much
 and
 it
 was
 a
 truly
 a
 privilege
 to

work
 with
 you.

  I
 would
 also
 like
 to
 thank
 Dr.
 Anthony
 Wilcox
 and
 Dr.
 Julie
 Downing
 for
 their

inspiration
 in
 pursuing
 a
 doctoral
 degree.
 I
 would
 not
 have
 made
 it
 this
 far
 without
 the

encouragement
 and
 support
 from
 both
 of
 you.
 Thanks
 also
 to
 Dr.
 Jay
 Penry
 and
 Becky

Johnson
 for
 your
 support
 and
 feedback
 on
 this
 dissertation.

  I
 would
 also
 like
 to
 thank
 Taryn
 Hand
 for
 all
 her
 assistance
 during
 each
 phase
 of
 my

dissertation.
 Not
 only
 did
 she
 commute
 to
 Bend
 to
 help
 with
 data
 collection,
 but
 she
 was

also
 there
 to
 help
 with
 whatever
 was
 needed.
 Thanks
 for
 being
 such
 a
 great
 friend.

  I
 would
 also
 like
 to
 thank
 Cheryl
 Pitkin
 and
 the
 Central
 Oregon
 Community
 College

for
 allowing
 me
 to
 use
 lab
 space
 to
 collect
 my
 data.
 Also
 thanks
 to
 Karin
 Hardin
 for
 driving

to
 Bend
 each
 week
 to
 oversee
 and
 assist
 with
 data
 collection.

  I
 wish
 to
 extend
 special
 thanks
 Dr.
 Enette
 Larson-­‐Mayer,
 for
 not
 only
 her
 guidance

during
 my
 laboratory
 analyses,
 but
 also
 for
 opening
 her
 home
 to
 me
 while
 I
 was
 working
 at

the
 University
 of
 Wyoming.

 Thanks
 to
 Kathleen
 Austin
 who
 took
 me
 under
 her
 wing
 and

assisted
 me
 in
 the
 lab,
 well
 into
 the
 middle
 of
 the
 night
 some
 days.

  Finally,
 I
 would
 like
 to
 thank
 my
 husband,
 Zach
 Violett,
 who
 allowed
 me
 to
 even

entertain
 the
 idea
 of
 moving
 to
 Corvallis
 to
 attend
 OSU.
 You
 have
 stood
 behind
 me
 for
 years

as
 I
 worked
 towards
 my
 degree.
 This
 is
 just
 as
 much
 your
 success
 as
 mine.
 Thank
 you
 for

your
 unconditional
 love
 and
 support.

It
 takes
 a
 village.
CONTRIBUTION
 OF
 AUTHORS

Dr.
 Melinda
 Manore,
 Dr.
 Enette
 Larson-­‐Meyer,
 and
 Dr.
 Julie
 Downing
 assisted
 with
 data

collection
 and
 analysis.

Chapter
 2.
 Dr.
 Brenda
 Alexander
 and
 Kathleen
 Austin
 assisted
 with
 laboratory
 analyses
 and

interpretation.
TABLE
 OF
 CONTENTS

 Page

Chapter
 1:
 Introduction
 .........................................................................................................................................
 1

1.1
 Appetite-­‐Regulating
 Hormones
 ..............................................................................................................................
 1

1.2.
 Subjective
 Appetite
 .....................................................................................................................................................
 3

1.3
 Exercise
 and
 Appetite
 .................................................................................................................................................
 3

1.4.
 Subject
 sex,
 size
 and
 level
 of
 fitness.
 ....................................................................................................................
 5

1.5.
 Contribution
 to
 the
 research
 literature
 ..............................................................................................................
 6

1.6.
 Application
 ......................................................................................................................................................................
 7

1.7.
 Local
 Relevance
 -­‐
 Oregon
 .........................................................................................................................................
 8

1.8.
 Research
 Goals
 ..............................................................................................................................................................
 9

1.9.
 Primary
 Aims
 .................................................................................................................................................................
 9

1.10
 References
 ..................................................................................................................................................................
 11

Chapter
 2:
 Exercise-­‐Trained
 Men
 and
 Women:
 Role
 of
 Exercise
 and
 Diet
 on
 Appetite
 and

Energy
 Intake
 ..........................................................................................................................................................
 14

2.1.
 Introduction
 ................................................................................................................................................................
 15

2.2.1.
 Impact
 of
 Diet
 ....................................................................................................................................................
 15

2.2.2.
 Impact
 of
 Exercise
 and
 Fitness
 Level
 ......................................................................................................
 16

2.2.3..
 Impact
 of
 Sex
 .....................................................................................................................................................
 17

2.2.
 Hormonal
 Regulation
 of
 Appetite
 ......................................................................................................................
 18

2.2.1.
 Insulin
 ...................................................................................................................................................................
 19

2.2.2.
 Leptin
 ....................................................................................................................................................................
 19

2.2.3.
 Ghrelin
 ..................................................................................................................................................................
 20

2.2.4.
 Cholecystokinin
 ................................................................................................................................................
 21

2.2.5.
 Glucagon-­‐Like
 Peptide
 1
 ...............................................................................................................................
 21

2.2.6.
 Peptide
 YY
 ...........................................................................................................................................................
 22

2.2.7.
 Sex
 Hormones
 ....................................................................................................................................................
 22

2.3.
 Assessment
 of
 Appetite
 ..........................................................................................................................................
 23

2.4.
 Exercise,
 Appetite,
 and
 Gut
 Hormones
 ............................................................................................................
 24

2.4.1.
 Acute
 Exercise
 (Aerobic
 and
 Resistance
 Exercise)
 ...........................................................................
 24

2.4.2.
 Exercise
 Intensity
 .............................................................................................................................................
 31

2.4.3.
 Sex
 Differences
 ..................................................................................................................................................
 32
2.4.4.
 Exercise
 Training
 .............................................................................................................................................
 33

2.5.
 Exercise
 and
 Energy
 Intake
 ..................................................................................................................................
 34

2.6.
 Diet
 and
 Appetite
 in
 Active
 Women
 ..................................................................................................................
 36

2.7.
 Diet
 ..................................................................................................................................................................................
 37

2.7.1.
 Low-­‐Energy
 Dense
 Diets
 ...............................................................................................................................
 37

2.7.2.
 Low-­‐Energy
 Diets
 and
 Exercise
 .................................................................................................................
 39

2.7.3.
 Other
 Potential
 Mechanisms
 for
 Appetite
 Suppression
 in
 Active
 Individuals
 ......................
 40

2.8.
 Conclusions
 ..................................................................................................................................................................
 41

2.9.
 References
 ....................................................................................................................................................................
 42

Chapter
 3:
 No
 effect
 of
 Exercise
 Intensity
 on
 Appetite
 in
 Highly-­‐Trained
 Endurance
 Females

 ........................................................................................................................................................................................
 50

3.1
 Methods
 ..........................................................................................................................................................................
 51

3.1.1.
 Subjects
 and
 Recruitment
 ............................................................................................................................
 51

3.1.2.
 Baseline
 Testing
 ................................................................................................................................................
 51

3.1.3.
 Experimental
 Protocol
 ...................................................................................................................................
 52

3.1.4.
 Exercise
 Trials,
 Gut
 Hormones
 and
 Appetite
 Assessments
 ...........................................................
 53

3.1.5.
 Body
 Composition
 ...........................................................................................................................................
 54

3.1.6.
 Subjective
 Appetite
 Assessment
 ................................................................................................................
 54

3.1.7.
 Hormone
 Analysis
 ............................................................................................................................................
 54

3.1.8.
 Statistical
 Analysis
 ...........................................................................................................................................
 54

3.2.
 Results
 ............................................................................................................................................................................
 55

3.2.1.
 Baseline
 Characteristics
 ................................................................................................................................
 55

3.2.2.
 Moderate
 and
 High
 Intensity
 Exercise
 Trials
 ......................................................................................
 56

3.2.3.
 Appetite
 Hormones
 .........................................................................................................................................
 57

3.2.4.
 Appetite
 Ratings
 ...............................................................................................................................................
 59

3.3.
 Discussion
 ....................................................................................................................................................................
 61

3.3.1.
 Sex
 Differences
 ..................................................................................................................................................
 62

3.3.2.
 Exercise
 Intensity
 .............................................................................................................................................
 62

3.3.3.
 Exercise
 and
 Appetite-­‐Regulating
 Hormones
 ......................................................................................
 63

3.4.
 Appetite
 Ratings
 ........................................................................................................................................................
 67

3.5.
 Strengths
 .......................................................................................................................................................................
 69

3.6.
 Limitations
 ...................................................................................................................................................................
 70

3.7.
 Conclusions
 ..................................................................................................................................................................
 70