EXERCISE AND ANXIETY SENSITIVITY Exercise and anxiety sensitivity

134 Pages·2014·2.03 MB·English

Exercise and anxiety sensitivity i

Running head: EXERCISE AND ANXIETY SENSITIVITY

Exercise and anxiety sensitivity: An examination of dose response,
credibility, expectancy, and perceived effort.
Thomas Newman

A dissertation submitted in partial fulfillment of the requirements for the degree of PhD in

Clinical Psychology

Supervisor: Dr. Gord Hayman

Second Reader: Dr. Michael Stones

Internal Examiner: Dr. Joey Farrell, & Dr. Derek Kivi
External Examiner: Dr. Nick Carleton Lakehead
University
Thunder Bay, Ontario

September, 2014
Exercise and anxiety sensitivity ii

Abstract

Despite ongoing research examining exercise and its anxiolytic effects (Petruzello, Landers,
Hatfield, Kubitz, & Salazar, 1991), our understanding of this relationship is limited. The present
study evaluated the effects of exercise on anxiety sensitivity (AS), and sought to evaluate the
effects of various exercise intensities as well as several potential moderating variables including
perceived effort, credibility, and expectancy. It was hypothesized that exercise at both mild and
moderate intensities would result in a reduction of AS compared to a no-exercise control
condition. In addition, it was hypothesized that perceived effort, credibility, and expectancy
would moderate the relationship between exercise, and AS. Fifty-five participants (37 females
and 18 males) were randomly assigned to one of three groups: 1) a no exercise control condition
(n=18), 2) a mild exercise condition (n=19), and 3) a moderate exercise condition (n =18). All
participants attended the lab a total of six times over a two week period, and completed measures
for perceived effort, credibility, expectancy, and AS. Results indicate that participants in the two
exercise conditions experienced a similar decrease in AS while those in the no exercise condition
experienced no significant change in AS. This finding suggests that a very mild dose of exercise
intervention is sufficient to improve scores of AS in an at risk population. Furthermore, the
variables of expectancy, credibility, and perceived effort did not moderate the effects of exercise
on AS.
Exercise and anxiety sensitivity 3

Acknowledgements

To all the people who made a difference, you already know who you are.

Thanks! Take Luck!
Exercise and anxiety sensitivity 4

Table of Contents
Abstract ........................................................................................................................................... ii
Acknowledgements ........................................................................................................................ iii
List of Appendices ........................................................................................................................ vii
List of Tables ............................................................................................................................... viii
List of Figures ................................................................................................................................ ix
Exercise and Mental Health ........................................................................................................ 3
Exercise Modalities..................................................................................................................... 4

Anxiety Sensitivity...................................................................................................................... 6

Proposed Mechanisms of Change ............................................................................................. 10

Proposed Physiological Mechanisms.................................................................................... 10

Proposed Psychological Mechanisms ................................................................................... 20

Dose Response .......................................................................................................................... 26

Ratings of Perceived Exertion .................................................................................................. 29

Credibility and Expectancy ....................................................................................................... 30

Previous Research ................................................................................................................. 33

Previous Anxiety Sensitivity Research ..................................................................................... 36

Limitations of Prior Research ............................................................................................... 42

Present Study ................................................................................................................................ 45

Hypotheses ................................................................................................................................ 47

Method .......................................................................................................................................... 47

Power Analysis ......................................................................................................................... 47

Participants................................................................................................................................ 47

Materials ................................................................................................................................... 49
Exercise and anxiety sensitivity 5

Anxiety Sensitivity Index. .................................................................................................... 49

Credibility and Expectancy Questionnaire. .......................................................................... 51

Borg’s Rating of Perceived Effort Scale............................................................................... 51

Physical Activity Readiness Questionnaire. ......................................................................... 52

Demographic Questionnaire. ................................................................................................ 52

Heart Rate Monitor. .............................................................................................................. 53

Treadmill............................................................................................................................... 53

Procedure .................................................................................................................................. 53

Experimental Conditions .......................................................................................................... 55

Experimental condition 1 - Moderate intensity exercise. ..................................................... 55

Experimental condition 2 -mildintensity exercise. ............................................................... 55

Experimental condition 3 - Resting control. ......................................................................... 55

Ethical Considerations .............................................................................................................. 56

Analyses .................................................................................................................................... 56

Results........................................................................................................................................... 57

Data Screening .......................................................................................................................... 57

Computing Variables ................................................................................................................ 59

Anxiety Sensitivity Analysis..................................................................................................... 59

Covariate Analysis .................................................................................................................... 62

Correlations ............................................................................................................................... 66

Regression Analysis of only Exercisers.................................................................................... 66

Discussion ..................................................................................................................................... 67

ASI Change Due to Exercise .................................................................................................... 69
Exercise and anxiety sensitivity 6

Dose Effect................................................................................................................................ 71

Prospective Explanation of Exercise Effects ............................................................................ 73

Moderators ................................................................................................................................ 75

Limitations .................................................................................................................................... 77

Future Directions .......................................................................................................................... 79

Conclusion .................................................................................................................................... 80

References ..................................................................................................................................... 82
Exercise and anxiety sensitivity vii

List of Appendices

Appendix A – Anxiety Sensitivity Index .................................................................................... 109

Appendix B – Credibility and Expectancy Questionnaire .......................................................... 112

Appendix C – Borg Rating of Perceived Exertion...................................................................... 114

Appendix D – Physical Activity Readiness Questionnaire ........................................................ 116

Appendix E – Participant Information Form/Consent Form ...................................................... 118

Appendix F – Screening/Demographic Questionnaire ............................................................... 121

Appendix G – Debriefing Letter ................................................................................................. 123
Exercise and anxiety sensitivity 8

List of Tables

Table 1 – Demographic Characteristics by Group........................................................................ 48

Table 2 – Physical Characteristics by Group ................................................................................ 49

Table 3 – Measurement Points for Questionnaires ....................................................................... 54

Table 4 – Descriptive Statistics for ASI Scores ............................................................................ 58

Table 5 – Means and S.D. for Covariates ..................................................................................... 62

Table 6 – Correlations Among ASI Total Scores and Change Scores ......................................... 64
Exercise and anxiety sensitivity 9

List of Figures

Figure 1 – Anxiety Sensitivity Total Scores ................................................................................. 59

Figure 2 – Mean Anxiety Sensitivity Change Scores Post and Follow-Up .................................. 60

Figure 3 – Mean Credibility Scores by Group ............................................................................. 62

Figure 4 – Mean Expectancy Scores by Group ............................................................................ 63

Figure 5 – Mean Perceived Exertion Scores by Group................................................................. 63
Exercise and anxiety sensitivity 1

Exercise and anxiety sensitivity: An examination of dose response,
credibility, expectancy, and perceived effort

The Greek philosopher Plato wrote, “Lack of activity destroys the good condition of
every human being, while movement and methodical physical exercise save it and preserve it”,
while Edward Stanley, a 19th century British statesman opined, “those who think they have not
time for bodily exercise will sooner or later have to find time for illness” (Quotations Book,
n.d.). Despite the many centuries that separate these two thinkers, their beliefs regarding the
importance of exercise and the consequences of inactivity are virtually identical. Interestingly the
idea of ‘exercise’ as definitive and repetitive movement for the sake of getting in shape, losing
weight, or improving health (Caspersen, Powell, & Christenson, 1985), would have been foreign
to our ancestors only three or four generations ago. That is not to say that they did not value
physical activity, but rather physical activity was simply an ingrained part of everyday life and
not one that required special attention. Physical activity several generations ago was attained
through chores such as chopping and stacking firewood for the winter or walking several miles
into town as the only, rather than an alternative, form of transportation. However, today’s society
views exercise as an often optional add-on to our already busy lives. As work, leisure, and the
population in general become more sedentary (Jebb, & Moore, 1999), the idea of exercise as
definitive and repetitive movement for the sake of maintaining and improving health, has
become much more important.

The degree of importance that current society has attributed to the idea of exercise is
revealed through the most basic examination of the internet or analysis of mainstream
advertising. A cursory internet search on topics such as ‘exercise’, ‘physical activity’, or ‘weight
loss’ will provide millions of sites claiming (for the right price), to be able to help shed pounds,
increase fitness, or tone abs. Additionally, television advertising and infomercials offer a