Self-reported physical fitness in frail older persons: reliability and validity of the Self-Assessment of Physical Fitness (SAPF).

In very old and/or frail older people living in long-term care facilities, physical inactivity negatively affects activities of daily living. The main reason to assess older adults' perceived fitness is to establish the relation with their beliefs about their ability to perform physical activity adjusted to daily tasks. The Self-Assessment of Physical Fitness scale was developed to address these needs. The aim of this study was to estimate the test-retest reliability and construct validity of the scale. 76 elderly people (M age = 86.0 yr., SD = 6.3) completed the test. Cronbach's a was .71. One-week test-retest reliability ICC's ranged from .66 (SAPF aerobic endurance and SAPF balance) to .70 (SAPF sum score). Concurrent validity with the Groningen Fitness Test for the Elderly was fair to moderate. Despite the limited number of participants (N = 76), results suggest that the scale may be useful as an assessment of perceived fitness in older adults.