The purpose of this study was to assess the reliability and validity of a Dutch translation of a questionnaire to measure self-efficacy in leisure-time physical activity. The questionnaire consisted of three subscales measuring three dimensions of self-efficacy. It was completed by 461 participants, 55–65 years old. Fifty-nine participants took part in a test-retest study. Factor analysis and correlations between the sum-scores of the 3 scales confirmed that each scale measures a different dimension of self-efficacy. The criterion-related validity of 2 of the scales was found to be moderate. All 3 scales had a satisfactory internal consistency, indicating that they are reliable. Stability was assessed with a test-retest procedure, which yielded satisfactory results for 2 of the 3 scales. The results revealed an improvement in self-efficacy for 2 of the scales over a 4-week time period. When outliers were excluded, satisfactory values were obtained for intraclass correlation coefficients between the first and second measurements.

The assessment of fitness is a component of a national project aimed at the enhancement of physical avtivity among sedentary older adults, aged 55-65 year in the Netherlands. Deterioration in physical functioning may be improved through an exercise programme. Research showed that enhancement of physical activity results in improved fitness, increased functional ability and health-related quality of life. Scientific results of the association between exercise and physical fitness in older adults is not sufficiently evidence-based in the Netherlands. In order to support health policy interventions 5.584 fitness tests of sedentary older adults were analyzed. The fitness was assessed by the Groninger Fitnesstest for Elderly (GFE). The analysis of physical fitness in sedentary older adults showed a lower fitness status among the age group 55-65 of age and women. Health risk factors such as overweight and having a chronic disease explained 88% of the variance between a low fitness and a high fitness profile.