I would like to develop a study about physical function and I have to build the protocol considering a valid rationale. Would anyone be so kind to help me with this?
Have you meant by " assess physical equation" an empirical equation that is capable to describe data of experimental measurements of particular physical tests.
I would like to test physical condition of participants but for practical reasons, I will not be able to perform tests but just self-report measures. Are there articles that give me a rationale to choose questionnaires rather than tests?
There is a scale of perceived effort for humans. It is called rating of perceived exertion (RPE), or Borg scale. There is a broad scientific background concerning this subject. Please fell free to contact me if you need further information.