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How we measure & Study
Physical Activity: Part 1
Chapter 3
Unit II: Chapter 1-7
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Measurement is the Heart of
Science
Enables researchers and health-care professionals to:
Specify
which aspects of physical activity are
important for a particular health outcome
Monitor changes in physical activity over time
Monitor the effectiveness of an intervention
Determine the prevalence of people guidelines
for physical activity
Unit II: Chapter 1-7
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What are the advantages and
disadvantages of using
questionnaires to assess one’s level
of PA and/or exercise?
+ Subjective Techniques to Assess
Physical Activity
Typically paper and pencil questionnaires.
 Easy
to administer
 Relatively inexpensive
 Can be used to assess a large sample of
individuals quickly
Unit II: Chapter 1-7
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What are the advantages and
disadvantages of using the 7 day
recall inventory?
+ Self Report Measures
7-Day Physical Activity Recall(*)
 Assesses a previous week’s moderate, hard and very
hard physical activity
 Calculation for METS
 Validity and Reliability are strong
 Will be used in study!
Advantages:
 Speed and ease of administration
 Calculation of total energy expenditure
 Occupational and leisure activities.
Disadvantage:
 Previous week may not provide typical participation
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Godin Leisure-time questionaire (1985)
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Calculations

Level of PA activity for the week
PA = (9 X strenuous) + (5 X moderate) + (3 X light)
Example: Strenuous = 3 X
Moderate = 6 X
Light = 14 X
Pa = (9X3) + (5X6) + (3X14) = 27+30+42 = 99
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There are two forms of the RPE or
Borg scale. What is the purpose of
each?
+ Self Report Measures
Ratings of Perceived Exertion
 Assesses single session intensity.
 Borg Scale
 1-10 used for exercise evaluation
 6-20 used to measure level of intensity
Advantages:
 Good
Reliability
 Good Validity
Disadvantage:
 No
Unit II: Chapter 1-7
frequency data
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Unit II: Chapter 1-7
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+ Self Report Measures-For Children
Early physical activity measures for children were completed
by parents or teachers
 Typically
were not valid or reliable
 7-Day Recall--invalid and unreliable
Previous Day Physical Activity Recall
 Good
Unit II: Chapter 1-7
Reliability
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+ Self Report Measures-For Older
Adults
Physical Activity Scale for the Elderly
 Assesses
a variety of physical activities of
daily living
 Specific cues for older adults
Advantages
 Quick
to complete
 Good validity and reliability
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What are the advantages and
disadvantages of using a dairy or
log to assess one’s level of PA
and/or exercise?
+ Diary or Log Methods
Typically completed at the end of each day & can be modified to
specific behaviors
Advantages
 No need for observation
 Detailed information can be obtained
Disadvantages
 Expensive to reduce the data to analyzable form
 Heavy participant burden
 Questionable validity due to tedium
Unit II: Chapter 1-7
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+ Self Report Measures-Overview
Many questionnaires are available to assess
physical activity
However there is no gold standard for
measurement
All self-report measures are associated with
error
They are relatively effective indicants of which
people are more or less active
Unit II: Chapter 1-7
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How we measure & Study
Physical Activity: Part 2
Chapter 3
Unit II: Chapter 1-7 20
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What are the advantages and
disadvantages of using motion
monitors to assess one’s PA and/or
exercise?
+ Objective Measures of Physical
Activity
Technology has only recently become
available to objectively assess the
minutes spent at different intensities of
physical activity.
Activity monitors have the potential to
provide substantial benefits over selfreport--they avoid the biases and
inaccuracies of recall.
Unit II: Chapter 1-7
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+ Pedometers
Pedometers are simple movement device counters that can
estimate habitual physical activity over a relatively long
period.
Less obtrusive devices
Light weight
 Clip onto a belt or are worn around the ankle

Limitations with the reliability and validity of mechanical and
electronic pedometers.
Low validity
 Some devices show high deviations from the
actual step rate
 Objective is to accumulate 10,000 steps per week

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What guidelines would you give
your clients if they use a
pedometer to be healthy and/or
lose weight? What if they were a
child or aged?
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Step Indices (Tudor-Locke & Bassett,
2004)
< 5,000 is Sedentary
5,000-7499 is Low active
7,500-9,999 is somewhat active
10,000-12,499 is active
>12,500 is Highly active
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How many steps should be taken?

Bench mark is 10,000 steps/day = 300-400 kcal/day

300-400 kcal/day X 7 days = 2100 – 2800 kcal/week

Need 9,000 steps/day = normal weight

Need 15,000 steps/day to achieve weight loss goals (Leermaker, Dunn, & Blair, 2000)

Children 8-10 years of age need 12,000-16,000 steps per day for health

Healthy adults need 7,000-13,000 steps per day for health

A workplace walking program that prescribes 10,000 steps/day reports a 88% attrition rate
(Irwane, et. at., 2000)

Older adults have difficulty in achieving 10,000 steps/day what is recommended is 6,000 – 8,500
steps per day.

A walking programs for women that requires 10,000 steps/day is associated with reduced
adherence (Sidman, 2002)

30 minute moderate-intensity walk results in 3,800-4,000 steps.
Unit II: Chapter 1-7
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How effective are heart rate
monitors in assessing PA and/or
exercise?
+ Heart Rate Monitors
Can provide minute-by-minute data for up to 48 hours.
Good validity
Limitations
 Heart rate monitors cannot distinguish accurately
between light and moderate intensity activities
 Elevated heart rates can be produced by mental
stress in the absence of physical activity
 Heart rate monitors can be inconvenient to use
 Various electronic devices interfere with the
recording resulting in lost data
Unit II: Chapter 1-7
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In Summary


Motion detector such as pedometers do:

Measure physical activity but they have variability and lack
precision.

Number of steps taken per day or per week provides one an
insight in their level of activity.
Heart rate monitors do:

Measure heart rate response to activity

Can can use them to monitor their heart rate during a workout

They are poor index to measure low to moderate exercise

Heart rate it self not a reliable index due to other factors such as
anxiety and fatigue can effect one HRT.
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How we measure & Study
Physical Activity: Part 3
Chapter 3
Unit II: Chapter 1-7 30
+ Direct Observation
Advantages:

It is accurate

It involves little inference with the participant’s routine

Diverse dimensions related to physical activity can be
quantified

It can be used as a criterion method for validating
other measures of physical activity
Limitations:

It is time-consuming

Observation is expensive

Observations may not reflect habitual physical activity
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Is the community we live in an
“active community?”

How does one gauge the activity level of their citizens?

What determines if one city citizens are more active then
another?
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Ways communities can measure PA
levels

Environmental
 Miles of trails per capita
 # of PA facilities per capita in schools
 Availability of facilities to the public
 # of programs for PA in community
 # of agencies that sponsor PA events
 Zoning regulations
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Behavioral Outcome Measures
 Observation of usage
 Membership in PA organizations (YMCA, Health clubs)
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Sales of selected PA equipment, videos, etc.
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Ways communities can measure PA
levels
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Policy & Regulations
 PE in K-12 curriculum
 Amount/% of local budget per capita devoted to physical
activity/recreation
 Density of recreation facilities & new construction
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Information
 % of health-care providers that engage the public to exercise
more
 # of worksite materials linked to PA
 % of schools offering curricula in grades k-12
 # of medical reports dealing with PA
 “Point of purchase” education materials on PA
Unit II: Chapter 1-7
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In summary

Direct observation is a valid method to measure PA but it is
time consuming

Environmental, behavioral measure, policies and regulation,
and information are the four measure use to determine if you
live in active community.

These four measures are commonly assessed to determine if the
city or community is ready for a physical activity program.