Contextual Measurement of Sources of Exercise Amotivation: The Revised Amotivation Toward Exercise Scale-2.

The aim of the study was to modify the Amotivation Toward Exercise Scale-2 by dropping the outcome amotivation beliefs subscale while retaining the capacity, effort, value, and task characteristics amotivation beliefs. Data from 515 Greek nonexerciser adults aged 19-64 years and 399 Greek nonexerciser older adults aged 65-82 years, men and women, supported the latent four-factor structure of the Revised Amotivation Toward Exercise Scale-2 scores within each sample separately. The hierarchical model was also supported. Measurement invariance of Revised Amotivation Toward Exercise Scale-2 scores was supported across groups of gender, age, body mass index, and educational levels within adults and older adults. Configural measurement invariance supported a replicable factor structure across adults and older adults. Metric and strong invariance was supported across middle-aged and older adults but not between younger and older adults. Full measurement invariance was supported between younger and middle-aged adults.