Method
Participants
The participants in this study were students
recruited from the undergraduate Physical Education General (PEG)-jogging
classes at Bowling Green State University. Three PEG-jogging classes were
scheduled for the spring 2012 semester, including PEG-2630 (13033) which met on
Mondays and Wednesdays from 10:30 a.m. to 11:20 a.m.; PEG-2630 (13034) which met
on Mondays and Wednesdays from 11:30 a.m. to 12:20 p.m.; and PEG-2630 (13035)
which met on Tuesdays and Thursdays from 11:30 a.m. to 12:20 p.m. Those classes
were held in the Perry Field House at Bowling Green State University. Each
class was capped at 30 students according to registration information. Seventy-five
students signed the Participant Consent Form and were willing to participate in
this study. After three study sessions, fifty-five students (N = 55), including 28 males and 27 females, completed the whole study. The mean age of the participants were 20.63
(SD = 1.404).
The exclusion criteria were students who were under
18 years of age at the time of the study, who were unable to complete 15
minutes of jogging and/or walking continuously, who had health problems that
preclude their participation, or who did not attend the second and/or third
study sessions. Participants exercised in each class as a group.
Instruments
General Information Questionnarie
A questionnaire has been developed to collect basic
information from the participants. Participants were asked about their gender,
age, grade, and ethnicity (See Appendix A for the questionnaire). One
additional question about exercise frequency were investigated. This
questionnaire provides additional information to understand the factors that
are related to mood states.
Paffenbarger Physical Activity Questionnaire
The Paffenbarger Physical Activity Questionnaire
(PPAQ) is a self-report inventory to calculate kilocalories which the participant
consumes per week (Pereira, 1997). There are total eight questions, including
multiple choice and open-ended questions. An example of these questions
includes “How many city blocks or their equivalent do they normally walk each
day?” (See Appendix B for the questionnaire.) The result of PPAQ were used to
estimate the participant’s fitness level.
Profile of Mood States Inventory
The Profile of Mood States (POMS) was designed to
measure mood alterations (McNair, Lorr, & Droppleman, 1992). Since the POMS
is commonly employed in exercise and mood alteration studies, results can be
compared with those from other studies. The POMS Standard Form were employed in
this study and contains 65 items rated on a 5-point scale (0 = not at all, 1 =
a little, 2 = moderately, 3 = quite a bit, and 4 = extremely). The six subscales
include tension-anxiety, depression-dejection, anger-hostility, vigor-activity,
fatigue-inertia, and confusion-bewilderment. The instruction for the state
measure of the POMS is “How do you feel right now?” (See Appendix C for the
inventory.) The internal consistency estimates for the POMS range from 0.84 to
0.95. The test-retest reliability coefficients range from 0.65 to 0.74 (McNair
et al., 1992).
Exercise Enjoyment
Exercise enjoyment were measured by the Physical
Activity Enjoyment Scale (PACES) developed by Kendzierski and DeCarlo (1991).
The PACES includes 18 items rated on a seven-point bipolar scale (e.g., I enjoy
it, I hate it; I feel bored, I feel interested). The PACES reliability of
internal consistency is 0.96. The test-retest reliability coefficient ranges
from 0.60 to 0.93 (Kendzierski & DeCarlo, 1991). Using different
instructions, the PACES can both measure the PACES-trait (in general, most of
time) and the PACES-state (at the moment). The instruction for the PACES-trait
measure is “Please rate how you feel about most types of physical activity in
general, most of the time” (see Appendix D for the inventory). The instruction
for the PACES-state measure is “Please rate how you feel at the moment about
the physical activity you have been doing” (see Appendix E for the inventory).
Rating of Perceived Exertion
Perceived exertion were measured using Borg’s (1998)
Ratings of Perceived Exertion (RPE) scale. Participants respond to the question
“How hard are you working?” on the RPE scale. The RPE scores range from 6 to 20
with verbal indicators (e.g., 6 = no exertion at all; 20 = maximum exertion)
(see Appendix F for the scale). The RPE scale is used to measure an individual’s
overall sensations and feelings of physical stress. Therefore, the rating
indicated by the individual represents the amount of overall exertion experienced
(Borg, 1998).
Heart Rate
Heart rate were used to reflect exercise intensity
and measured by a Polar heart rate monitor (Polar Model S120TM,
Kempele, Finland) during exercise. Exercise intensity can be represented by the
percentage of Heart Rate Reserved (HRR). According to ACSM (2010, p. 5), the formula
for the percentage of HRR is as follows:
%HRR
= % (age-predicated maximal HR－resting HR) + resting HR;
The newer formula for predicting maximal heart rate were used in this study (ACSM,
2010, p. 155). The formula is as follows:
Age-predicated
maximal HR = 206.9 – (0.67 × age).
Therefore, the percentage of HRR (exercise intensity) can be calculated by using the two
formulas. For example, a 20 year old college student’s age-predicated maximal
HR is 193.5. If this college student’s resting heart rate is 70 and his average
heart rate during 15 minutes of jogging is 140, his heart rate ranges for low,
moderate, and high exercise intensity can be calculated (see Table 2).
Therefore, this student’s exercise intensity is moderate.
Table 2
Heart rate ranges for different
intensities on a 20-year old participant
|
Intensity HHR (%) |
Heart rate |
|
Low 20-39% |
94.7-118.2 |
|
Moderate 40-59% |
119.4-142.9 |
|
High 60-84% |
144.1-173.7 |
Procedure
Approval for the study were sought from the School
of Human Movement Sports and Leisure Studies Executive Committee and the Human
Subjects Review Board (HSRB) at Bowling Green State University. Before the study
begins, the two PEG-jogging instructors were asked to permit this study to be
conducted in their classes.
Day 1, Week 7 of the Semester (first class of this week): Orientation Session
An orientation session was conducted during the 7rd
week of the spring semester in order to recruit students for this study. At the
beginning of the orientation, the purpose of this study was explained to the students
(see Appendix G). Students who decided to participate in the study signed the Participant
Informed Consent Form (see Appendix H), as well as completed the General
Information Questionnaire (see Appendix A), Paffenbarger Physical Activity
Questionnaire (see Appendix B), and Physical Activity Enjoyment Scale-trait
(see Appendix D). Each participant had a unique testing ID comprised of the
first two letters of the participant’s mother’s first name and the last four
digits of the participant’s telephone number to protect the participant’s
privacy (see Appendix H).
Day 2, Week 7 (second class of this week): Continued Orientation Session for Use of Heart Rate Monitor and Rating of Perceived Exertion Scale
In the second orientation session, the researchers taught the participants how to wear and
use the heart rate monitors in the class room (see Appendix J) besides the
track. Also, participants’ resting heart rates were collected.
Each participant was given a heart rate monitor,
including a transmitter, an elastic strap, and a wrist receiver. Then, the researcher
demonstrated how to wear, start, and end the heart rate monitor. After wearing
the heart rate monitor, all participants sat in the chair quietly for three
minutes, and recorded their resting heart rates at 0:50, 1:50, 2:50, 3:50, and
4:50 on the recording paper (see Appendix I). The third time (2:50) of resting
heart rate were considered as the resting heart rate. After measuring resting
heart rate, the researcher reviewed the RPE scoring system with students. Then,
participants practiced using heart rate monitors while they jogged at the
preferred intensity. Also, participants yelled out their RPE when they pass by
the researcher each time as practice. Throughout the process, participants
would familiar with the heart rate monitor, RPE scoring system, and the
procedure of the study.
In order to avoid disturbance, participants were
asked to jog without mobile phones and other sources of electromagnetic
interference. Moreover, participants were instructed to remain three feet away
from each other to protect the accuracy of the monitor’s functioning.
Day 3, Week 8: Exercise Testing
The exercise testing session started the 8th
week of spring semester. Before exercise, the researcher reviewed the RPE scoring
system again, and participants completed the POMS on how they feel at the
moment. Next, participants attached HR monitors and color tapes. Participants were
instructed to select an intensity that they can sustain for 15 minutes and that
they would feel happy to do regularly (Parfitt, Rose & Maekland, 2000). Then,
all participants jogged and/or walked for 15 minutes at their preferred
intensity levels.
All participants started and finished exercising at
the same time based on the researcher’s directions. The researcher blew a
whistle in order to let students know when to start and to end exercising. At
the same time, the researcher pushed the start button of the timer.
Participants were told to exercise alone to avoid
the social effects of talking with others and the interference of other heart
rate monitors. The researcher and research assistants recorded the heart rate through
the wrist receiver and their RPE when participants pass by on the track each
lap (see Appendix L).
Six researchers (the researcher trained research assistants)
worked in pair at three different locations on the track to oversee
approximately eight students per pair. Each group of eight participants worn
the same color label displaying their testing ID for identification purpose. The
researcher and research assistants also recorded the number of laps each
participant completes (see Appendix L). Participants stopped exercising when the
researcher blows the whistle and cooled down for one minutes. After cooling
down, all participants walked back to the class room and completed the POMS and
the PACES-state. (See Table 3 for the time lines.)
Data Analysis
The purposes of this study are to examine whether desirable
mood changes will occur if the participants exercise at their preferred
intensity levels, to examine the relationship between mood changes and exercise
enjoyment, as well as to examine the characteristics of the preferred intensity
in college students. Based on these purposes, the following five hypotheses
will be analyzed.
The six subscales on the POMS can be combined into a
Total Mood Disturbance (TMD) score by summing the scores for the five negative
mood subscales (tension, depression, anger, fatigue, and confusion), and
subtracting the score for vigor. In this study, the independent variables are two
measurement times (pre- and post- exercise) and exercise enjoyment levels (low
and high). The dependent variables are mood scores measured by the POMS and the
TMD scores. The categorical variable is gender.
Hypothesis# 1: Participants will have positive mood
changes after jogging 15 minutes. The statistical analysis will be a one-way
MANOVA with repeated-measures on the six POMS subscales. This will be used to examine
mood alteration associated with two measurement times (pre- and post- exercise).
Hypothesis# 2: Participants who report higher
exercise enjoyment trait scores will have more significant mood changes. Exercise
enjoyment trait scores will be divided into two groups: low (50% of scores
below the median) and high (50% of scores above the median). The statistical analysis
will be a 2 (exercise enjoyment levels: low and high) × 2 (time: pre- and
post-exercise) repeated-measures ANOVA on the TMD score to compare the differences
in mood changes between the two exercise enjoyment levels. Also, a 2 (exercise
enjoyment levels: low and high) × 2 (time: pre- and post-exercise)
repeated-measures MANOVA on the six POMS subscales will be examined to compare
the differences in mood changes between the two exercise enjoyment levels.
Hypothesis# 3: Participants who report higher exercise
enjoyment state scores after exercise will have more significant mood changes. Exercise
enjoyment state scores will be divided into two groups: low (50% of scores
below the median) and high (50% of scores above the median). The statistical analysis
will be a 2 (exercise enjoyment levels: low and high) × 2 (time: pre- and
post-exercise) repeated-measures ANOVA on the TMD score to compare the differences
in mood changes between the two exercise enjoyment levels. Also, a 2 (exercise
enjoyment levels: low and high) × 2 (time: pre- and post-exercise)
repeated-measures MANOVA on the six POMS subscales will be examined to compare
the differences in mood changes between the two exercise enjoyment levels.
Hypothesis# 4: Females will choose lower intensity
as their preferred intensity than males. The statistical analysis will be a 2
(gender) × 5 (time: before warm-up, after warm-up, the 4th, 9th,
and 14th minute of exercise) repeated-measures ANOVA on the
participants’ heart rates.
Hypothesis# 5: When exercising at a preferred
exercise intensity level, more college students will choose a moderate
intensity rather than a high or low intensity as their preferred exercise
intensity. According to ACSM (2010, p. 5), low exercise intensity ranges from 20
to 39% of heart rate reserve, moderate exercise intensity ranges from 40 to 59%
of heart rate reserve, and high exercise intensity ranges from 60-84%
of heart rate reserve. The statistical analysis will be
the Chi-Square Test on 2 (female and male participants) × 3 (low, moderate, and
high intensity) on participants’ heart rates.
Table 3
The schedule for the study
|
Activity |
Time |
|
|
Orientation Session |
|
|
|
The 7th week (first class) |
|
10 min 5 min 15 min 5 min |
|
The 7th week (second class) |
|
10 min 5 min 5 min 25min |
|
Testing Session |
||
|
The 8th week
|
|
5 min 5 min 5 min 15 min 10 min |