1. Measurement of Physical Activity EPHE 348

2. Why is measurement of PA Important? To specify which aspects are important To monitor changes To evaluate interventions To determine prevalence To predict with accuracy

3. Aspects to Measure Frequency Duration Intensity Type

4. Techniques Criterion (direct observation) Objective (accelerometer) Subjective (questionnaire)

5. Popular Activities Walking (65%) Gardening (41%) Home Exercise (24%) Cycling/Swimming (18-19%) Strength training (11%) Exercise classes (7%)

6. Key Aspects of Measurement Reliability Validity

7. Advantages of Self-Report Easy to use Inexpensive Easy to score Can administer quickly

8. Limitations of Self-Report Social desirability Memory Immediacy/recency Familiarity of terminology

9. Objective Measures Heart rate monitors Pedometers Accelerometers

10. Example of Accelerometry

11. Objective vs. Self-Report 83 study systematic review of adolescents and children (Adamo et al., 2008). Correlations of -.56 to.89 between measures and 72% of studies showed over-estimation with self-report. 187 study systematic review of adults (Prince et al. 2008). Correlations of -.71 to.96 between measures (M =.37). No discernable differences in terms of over or under-estimation, but estimation was poorest for vigorous activity.

12. Issues with self-report Response values provided can bias the measure. Courneya, K.S., Jones, L.W., Rhodes, R.E. & Blanchard, C.M. (2004). Effects of different combinations of intensity categories on self-reported exercise. Research Quarterly for Exercise and Sport, 75, 429-433.

14. Issues with self-report Intensity categories provided can influence accuracy Courneya, K.S., Jones, L.W., Rhodes, R.E., & Blanchard, C.M. (2003). Effect of response scales on self-reported exercise frequency. American Journal of Health Behavior, 27, 613-622.