My history includes Cedars-Sinai Spine Center as well as giving fitness testing at Tony Robbins Seminars. As an orthopedic physical therapist with 2 personal training degrees, ACSM and ISSA, in this day and age I advise anybody starting out with a new work out program to visit a physical therapist first and a) get your body aligned, both the bones and the muscles, b) learn how to sit straight, stand correctly and lift properly so that you learn how to use your muscles properly and c) do some core training either with your physical therapist or with a pilates instructor before doing an intense workout.
Physical Therapy is now transitioning into preventative health. California and many other states now have direct access, where you can go to a physical therapist before you go to a doctor to relieve your pain and learn how to understand how to do ANY exercise with good form.
For e.g. if someone is looking to run a marathon, I re-align their spine and put them on the tredmill in front of a mirror and we go over how the patient is running so that they can connect what they are doing with what they are feeling. Once you know how your body works, any of these higher level programs will be done with proper form and you will avoid coming to a physical therapist later for the longer cleanup if you injure yourself. In this case, knowledge is power.