MEASURING PHYSICAL ACTIVITY Week 3

What you need to know The difference between subjective and objective methods The difference between subjective and objective methods What are: self-report, heart rate telemetry, pedometry accelerometry, observational tools? What are: self-report, heart rate telemetry, pedometry accelerometry, observational tools? What are the advantages and disadvantages of each method? What are the advantages and disadvantages of each method?

Introduction Why would the general population want to measure physical activity? Why would the general population want to measure physical activity? It can be quite a difficult task It can be quite a difficult task There are a number of options to assess physical activity There are a number of options to assess physical activity They are usually grouped as either They are usually grouped as either Subjective: our own perceptions Subjective: our own perceptions Objective: solid data or observations Objective: solid data or observations Each method has a range of advantages and disadvantages Each method has a range of advantages and disadvantages This includes practicality v. accuracy This includes practicality v. accuracy

Subjective Methods of Measuring Physical Activity Self report: Self report: Diary Diary Log book Log book Self-administered recall Self-administered recall Interviewer-administered recall Interviewer-administered recall Proxy reports Proxy reports

Activity Over the next week you are required to keep a diary of all the physical activity you participate in Over the next week you are required to keep a diary of all the physical activity you participate in Think about the domains of activity (occupational, household, active transport, leisure) Think about the domains of activity (occupational, household, active transport, leisure) Record information on F, I, D, T Record information on F, I, D, T

Subjective Methods of Measuring Physical Activity Advantages Advantages Quick and easy Quick and easy Cost effective Cost effective Suitable for individuals, small or large groups Suitable for individuals, small or large groups Can be quantitative and qualitative Can be quantitative and qualitative Disadvantages Disadvantages Reliability and validity problems Relies on honesty Not suitable for those with cognitive limitations (young and elderly)

Objective Methods of Measuring Physical Activity Heart rate telemetry Heart rate telemetry Pedometry Pedometry Accelerometry Accelerometry Observational tools Observational tools

Heart Rate Telemetry Records ______ _____ ________ (bpm) on a watch and can be transferred to a computer Records ______ _____ ________ (bpm) on a watch and can be transferred to a computer There is a ___________ between HR and energy expenditure There is a ___________ between HR and energy expenditure

Heart Rate Telemetry Advantages Advantages Strong link to energy expenditure Strong link to energy expenditure Low participant burden Low participant burden Clear in describing I, F, D Clear in describing I, F, D Quick and easy data collection Quick and easy data collection Disadvantages Disadvantages Expensive for large numbers Some discomfort Restricted to aerobic activities Influenced by other factors (age, stress, emotions)

Pedometry Device that records the _______ of steps taken and estimates the stride length (distance) and energy expenditure Device that records the _______ of steps taken and estimates the stride length (distance) and energy expenditure Worn on the hip Worn on the hip Responds to vertical forces Responds to vertical forces For health benefits you should be aiming for _______ steps/day For health benefits you should be aiming for _______ steps/day

Pedometry Advantages Advantages In-expensive In-expensive Small, lightweight, non-intrusive Small, lightweight, non-intrusive Useful in a variety of settings Useful in a variety of settings Easy to administer Easy to administer Measures a common activity Measures a common activity Immediate feedback Immediate feedback Potential to promote behaviour change Potential to promote behaviour change Disadvantages Disadvantages Assesses only walking Cannot record F, I, D Participant tampering Potential to be reactive (participant increases activity due to being monitored)

Accelerometry Motion sensors worn on the hip to assess the ___________ of the body in certain directions Motion sensors worn on the hip to assess the ___________ of the body in certain directions Provides detail on F, I, D Provides detail on F, I, D Provides minute-by-minute data Provides minute-by-minute data Detects movement ________ Detects movement ________

Accelerometry Advantages Advantages Small, lightweight and non-invasive Small, lightweight and non-invasive Clear in describing F, I, D Clear in describing F, I, D Simple, quick data collection Simple, quick data collection Records in real time (minute by minute) Records in real time (minute by minute) Disadvantages Disadvantages Expensive for large groups Inaccurate assessment of some activities Can’t specify T of activity

Observational Tools Watching people’s _________ within specific settings Watching people’s _________ within specific settings Can collect data across a range of areas: F, I, D, T Can collect data across a range of areas: F, I, D, T A variety of methods A variety of methods BEACHES BEACHES SOFIT SOFIT SOPLAY SOPLAY

Observational Tools Advantages Advantages Excellent qualitative and quantitative data Excellent qualitative and quantitative data Specific physical activity behaviours can be observed Specific physical activity behaviours can be observed Useful in a variety settings Useful in a variety settings Easily combined with software packages Easily combined with software packages Can collect contextual information Can collect contextual information Disadvantages Disadvantages Training needed for observer Presence of observer may bias behaviour Highly labour intensive and time consuming

Summary of Methods of Measuring Physical Activity Complete the summary table Complete the summary tablesummary tablesummary table