Presentation on theme: "How we measure & Study Physical Activity: Part 1"— Presentation transcript:
1 How we measure & Study Physical Activity: Part 1 Chapter 3Unit II: Chapter 1-7
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 outcomeMonitor changes in physical activity over timeMonitor the effectiveness of an interventionDetermine the prevalence of people guidelines for physical activityUnit II: Chapter 1-7
3 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 administerRelatively inexpensiveCan be used to assess a large sample of individuals quicklyUnit II: Chapter 1-7
5 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 activityCalculation for METSValidity and Reliability are strongWill be used in study!Advantages:Speed and ease of administrationCalculation of total energy expenditureOccupational and leisure activities.Disadvantage:Previous week may not provide typical participationUnit II: Chapter 1-7
10 Godin Leisure-time questionaire (1985) Unit II: Chapter 1-7
11 Calculations Level of PA activity for the week PA = (9 X strenuous) + (5 X moderate) + (3 X light)Example: Strenuous = 3 XModerate = 6 XLight = 14 XPa = (9X3) + (5X6) + (3X14) = = 99
12 There are two forms of the RPE or Borg scale There are two forms of the RPE or Borg scale. What is the purpose of each?
13 Self Report Measures Assesses single session intensity. Ratings of Perceived ExertionAssesses single session intensity.Borg Scale1-10 used for exercise evaluation6-20 used to measure level of intensityAdvantages:Good ReliabilityGood ValidityDisadvantage:No frequency dataUnit II: Chapter 1-7
15 Self Report Measures-For Children Early physical activity measures for children were completed by parents or teachersTypically were not valid or reliable7-Day Recall--invalid and unreliablePrevious Day Physical Activity RecallGood ReliabilityUnit II: Chapter 1-7
16 Self Report Measures-For Older Adults Physical Activity Scale for the ElderlyAssesses a variety of physical activities of daily livingSpecific cues for older adultsAdvantagesQuick to completeGood validity and reliabilityUnit II: Chapter 1-7
17 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 MethodsTypically completed at the end of each day & can be modified to specific behaviorsAdvantagesNo need for observationDetailed information can be obtainedDisadvantagesExpensive to reduce the data to analyzable formHeavy participant burdenQuestionable validity due to tediumUnit II: Chapter 1-7
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 activeUnit II: Chapter 1-7
20 How we measure & Study Physical Activity: Part 2 Chapter 3Unit II: Chapter 1-7
21 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.Unit II: Chapter 1-7
23 Pedometers Light weight Clip onto a belt or are worn around the ankle Pedometers are simple movement device counters that can estimate habitual physical activity over a relatively long period.Less obtrusive devicesLight weightClip onto a belt or are worn around the ankleLimitations with the reliability and validity of mechanical and electronic pedometers.Low validitySome devices show high deviations from the actual step rateObjective is to accumulate 10,000 steps per weekUnit II: Chapter 1-7
24 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?
25 Step Indices (Tudor-Locke & Bassett, 2004) < 5,000 is Sedentary 5, 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 = kcal/daykcal/day X 7 days = 2100 – 2800 kcal/weekNeed 9,000 steps/day = normal weightNeed 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 healthHealthy adults need 7,000-13,000 steps per day for healthA 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
27 How effective are heart rate monitors in assessing PA and/or exercise?
28 Heart Rate MonitorsCan provide minute-by-minute data for up to 48 hours.Good validityLimitationsHeart rate monitors cannot distinguish accurately between light and moderate intensity activitiesElevated heart rates can be produced by mental stress in the absence of physical activityHeart rate monitors can be inconvenient to useVarious electronic devices interfere with the recording resulting in lost dataUnit II: Chapter 1-7
29 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 activityCan can use them to monitor their heart rate during a workoutThey are poor index to measure low to moderate exerciseHeart rate it self not a reliable index due to other factors such as anxiety and fatigue can effect one HRT.
30 How we measure & Study Physical Activity: Part 3 Chapter 3Unit II: Chapter 1-7
31 Direct Observation Advantages: It is accurate It involves little inference with the participant’s routineDiverse dimensions related to physical activity can be quantifiedIt can be used as a criterion method for validating other measures of physical activityLimitations:It is time-consumingObservation is expensiveObservations may not reflect habitual physical activityUnit II: Chapter 1-7
32 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 EnvironmentalMiles of trails per capita# of PA facilities per capita in schoolsAvailability of facilities to the public# of programs for PA in community# of agencies that sponsor PA eventsZoning regulationsBehavioral Outcome MeasuresObservation of usageMembership in PA organizations (YMCA, Health clubs)Sales of selected PA equipment, videos, etc.Unit II: Chapter 1-7
34 Ways communities can measure PA levels Policy & RegulationsPE in K-12 curriculumAmount/% of local budget per capita devoted to physical activity/recreationDensity of recreation facilities & new constructionInformation% 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 PAUnit II: Chapter 1-7
35 In summaryDirect observation is a valid method to measure PA but it is time consumingEnvironmental, 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.