Which of the following would be the most reliable source to consult when creating a safe strength training routine?
an article published by a physical therapist
a program recommended by a pro athlete
a video showing army boot camp exercises
a list of exercises a friend already uses

A physical therapist is trained and educated in their field. Professional athletes do not have this education all of the time. Boot camp exercises may not be entirely safe, and sometimes it is difficult to understand what is going on in a video. A friend, obviously, is not a professional. Therefore, a physical therapist's word is the most reliable.

D. speep