Objective measures of pa
- 1. Measurement of Physical Activity Objective Measures
- 2. We also measure PA levels to: • Evaluate current guidelines and trends S • Set recommended levels of physical activity • Investigate the relationship between physical activity and health conditions • Allow research to be conducted on large numbers of people, allowing us to generalise about a wider population.
- 4. Objective measures Often rely on solid data or observations Predominantly used for the measurement of individuals Collecting physiological data/movement monitoring can reduce reactivity or social desirability bias Generally used in small scale studies
- 5. Heart Rate Telemetry Usually a watch Measure the participants responses to exercise via their heart rate Typically used to estimate oxygen uptake and therefore energy expenditure
- 6. Heart-rate Telemetry Advantages Disadvantages Specific physiological parameters Limited use in large numbers due to cost Easy to use Some discomfort to participants, especially over extended periods Clear in describing intensity, frequency and duration Use restricted to aerobic activities Simple, quick data collection Variations in heart rate need to be considered (age, heat, stress, emotions etc) Potential to provide educational information Calibration needed to each individual
- 7. Accelerometers An accelerometer is an electronic device used to assess the acceleration of the body in certain directions. An accelerometer device is able to provide detail on the frequency, duration and intensity of the physical activity being performed Provide minute-by-minute information that can be downloaded to a computer for analysis detect movement patterns throughout a day (e.g. how much time a child spends in moderate and/or vigorous physical activity).
- 8. Accelerometers Advantages Disadvantages Clear in describing intensity, frequency and duration Limit use in large numbers due to financial cost Non-invasive Inaccurate measure of some activities (incline walking, weights) Able to provide minute by minute information Usable for extended periods Simple, quick data collection Inability to provide behavioural data (what people are doing during recording)
- 9. Pedometers The original motion sensor for measuring physical activity Designed to count steps using a metronome that detects vertical movement Useful to measure distance traveled when you know the stride length of the participant 10000 steps is considered equivalent to meeting the NPAG
- 10. Pedometers Advantages Inexpensive Non-invasive Disadvantages Some accuracy lost when running/jogging Useful in a variety of settings (school, work) Possibility to tamper with results Easy to administer to large groups Assessment restricted to walking Potential to promote behavioural change Potential to be reactive Able to measure a common activity
- 11. Direct Observation Aims to measure physical activity type, time, place (context) Direct observation tools include: BEACHES SOFIT The most accurate of all objective measures, however the least practical SOPLAY
- 12. Direct Observation It is very useful for assessing the activity levels of children. It can be used in conjunction with other methods, such as accelerometry, to provide a more accurate description of physical activity levels. It can be time consuming. However, software products have become available that enable observations to be entered, stored and analysed, making the process more useful and appealing.
- 13. Direct Observation Advantages Able to provide excellent qualitative and quantitative information. Able to target specific physical activity behaviours Able to ease data collection and recording through available software programs Disadvantages Training required for observer Number of participants limited due to labor-intensive data collection Potentially reactive Usage limited to a confined setting (playground)
- 14. Summary of different PA measurement tools - Objective
- 15. Effectiveness of an intervention The only way we can determine whether a physical activity program increases a person’s physical activity behaviour is to: • measure their physical activity prior to the introduction of the program (pre-intervention or baseline testing) • repeat the assessment during the intervention or using identical measures at the conclusion of the program (post-test or post-intervention) • repeat the assessment again some time later, such as 12 months after post- intervention. (This is known as follow-up.)
Editor's Notes
- #12: Behaviours of eating activity for childrens healthSystem for observing fitness instruction timeSystem for observing play and leisure activity in youth