Table 2.

Specific Methodological Challenges to Physical Activity Intervention Research with Older Adult Subjects

Sampling Issues	Fear of risk of injury from physical activity
	Fear of exacerbation of prior medical conditions
	Attribution of low levels of physical activity to aging
	Poor perceived benefits versus risks of physical activity
	Need for prior medical clearance to participate in physical activity
Data Measures and Collection	Unfamiliarity with technology such as pedometers or accelerometers
	Functional status or co-morbidities affecting ability to calibrate or work with measurement instruments
	Lack of motivation for maintaining activity logs
	Availability of age-appropriate physical activity questionnaire (e.g., PASE, YPAS, CHAMPS)
	Inability to maintain study protocols due to lack of transportation, hospitalization, fatigue, compliance