+ How we measure & Study Physical Activity: Part 1 Chapter 3 Unit II: Chapter 1-7 1 + 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 2 + 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 4 + 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 Unit II: Chapter 1-7 6 + Unit II: Chapter 1-7 7 + Unit II: Chapter 1-7 8 + Unit II: Chapter 1-7 9 + Unit II: Chapter 1-7 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? + 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 13 + Unit II: Chapter 1-7 14 + 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 15 + 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 Unit II: Chapter 1-7 16 + 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 18 + 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 19 + How we measure & Study Physical Activity: Part 2 Chapter 3 Unit II: Chapter 1-7 20 + 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 22 + 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 Unit II: Chapter 1-7 23 + 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. Unit II: Chapter 1-7 + 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 28 + 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. + 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 Unit II: Chapter 1-7 31 + 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. Unit II: Chapter 1-7 + 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 Unit II: Chapter 1-7 + 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.