+ How we measure & Study Physical Activity: Part 1 Chapter 3 Unit II: Chapter 1-7 1

Unit II: Chapter 1-7

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How we measure & Study Physical Activity: Part 1

Chapter 3

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2+ 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

+What are the advantages and disadvantages of using questionnaires to assess one’s level of PA and/or exercise?


4+ 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

+What are the advantages and disadvantages of using the 7 day recall inventory?


6+ 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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10+Godin Leisure-time questionaire (1985)

+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

+There are two forms of the RPE or Borg scale. What is the purpose of each?


13+ 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 frequency data


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15+ 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 Reliability


16+ 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

+What are the advantages and disadvantages of using a dairy or log to assess one’s level of PA and/or exercise?


18+ 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


19+ 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


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+What are the advantages and disadvantages of using motion monitors to assess one’s PA and/or exercise?


22+ 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 self-report--they avoid the biases and inaccuracies of recall.


23+ 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

+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?

+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


26+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.

+How effective are heart rate monitors in assessing PA and/or exercise?


28+ 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

+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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31+ 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

+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?


33+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

Behavioral Outcome Measures Observation of usage Membership in PA organizations (YMCA, Health clubs) Sales of selected PA equipment, videos, etc.


34+Ways communities can measure PA levels

Policy & Regulations PE in K-12 curriculum Amount/% of local budget per capita devoted to physical

activity/recreation Density of recreation facilities & new construction

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

+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.

Documents

+ How we measure & Study Physical Activity: Part 1 Chapter 3 Unit II: Chapter 1-7 1