Measuring physical activity Flashcards
Benefits and downsides of various methods of measuring PA
What are the dimension of measuring physical activity?
FITT: frequency, intensity, time, type
What is the importance for accuracy of measuring PA?
Develop PA guidelines by exploring dose-response relationship; monitor compliance with PA within a population
What does validity mean?
Accurately measures
What does reliability mean?
Gives consistent results, precise
What does a greater r-value signify?
Greater association
What category of methods can be used to measure PA?
Energy expenditure, self-report, motion sensors
What are methods of measuring energy expenditure?
Indirect calorimetry, double labelled water, and direct calorimetry
What are the pros and cons of indirect calorimetry?
Pros: can be portable
Cons: portable is expensive and may alter behaviour; non-portable only in lab environment
What is Doubly-labelled water?
Measures difference in heavy oxygen and heavy hydrogen to produce loss of carbon dioxide
What are the cons of DLW?
Expensive, only provides total EE (doesn’t look at diet, PA, BMI)
What is direct calorimetry?
Measures heat given off
What are the cons of direct calorimetry?
Doesn’t allow rapid change in EE to be monitored (e.g. sprints); Doesn’t account for heat from other sources (overestimation); Heat may not be immediately lost from body (underestimation)
What are the pros and cons of self-reports?
Pros: cheap, easy
Cons: biased, lacks sensitivity (grouped into categories), unreliable as rely on recall
How are self-reports improved?
Activity diaries and recognition memory
What are the pros and cons of pedometers?
Pros: cheap, easy
Cons: counts total PA; can’t tell what type or intensity of PA; may skew results as self-monitoring; may put on pets
