Analyzing and explaining health-related behaviors and related factors require appropriate instruments for measurement. One of these tools is the questionnaires, which is particularly important in science, health education (
31,
32). Several questionnaires have been developed and used so far to measure social cognitive theory constructs to explain physical activity. The results showed the questionnaire developed in this study for psychometric evaluation of social cognitive theory constructs related to physical activity in women has acceptable reliability and validity. The strength of this study is an appropriate number of samples (n = 360) to the target group. The developed questionnaire is based on a theory in which four important constructs of social cognitive theory were used, while in most studies, one or two constructs of one model has been examined (
20,
21). In this study, we tried to fully state the validity and reliability of tools stages clearly and completely. Reliability and validity of questionnaires and psychometric evaluation procedures have not been clearly and completely stated, and they reported only the results of previous papers (
33,
34). One of the main features of a questionnaire is its compliance with cultural, linguistic, and local conditions of the target population. Accordingly, this study examined questionnaires in terms of observing the translation principles and cultural adaptability with the Persian language in a committee consisting of 5 experts. This issue is usually overlooked in other studies (
35,
36). To validate the questionnaire and to assess CVI and CVR in this study, the views of 20 experts from the fields of health education were used. This could increase the scientific validity of the questionnaire, while views of less number of experts have been used in most studied related to physical activity (
20,
37). The results of studies conducted by Ievers-Landis and Rovniak have identified social cognitive theory as an appropriate model to explain physical activity (
33,
38). Cronbach’s alpha of the PAQ-SCT was equal to 0.919 (0.925 - 0.949), which was very appropriate (
39). The results of this study are in line with the results of other studies, that consider Cronbach’s alpha reliability, higher than 0.7 as sign of scientific validity of the questionnaire (
36,
40). In this study, four scales of social cognitive theory were examined where Cronbach’s alpha of all was higher than 0.9 (
Table 5). The results of similar studies could confirm the reliability of the questionnaire in this study (
36,
41). In this study, self-regulation (R
2 = 0.97) was the most important predictor of physical activity. In studies conducted by Khani Jeyhuni and Wolfe, self-regulation has been introduced as the most important predictor of physical activity (
42,
43). Additionally, the Tan study results showed that self-regulation is one of the most important factors in physical activity (
44). Consistency of results of this study with mentioned studies shows that four scales developed to measure physical activity have appropriate and acceptable validity and reliability.
Limitations of the study include the large number of questions in the questionnaire, responding to the questions in the form of self-reporting, and short time of the research.