The effect of high-intensity strength training as compared to standard medical care on muscle strength, physical function and health status, in patients with Rheumatoid Arthritis Functional Class II. Which one is more effective?
This past summer, Marilyn Moffatt, PT, FAPTA stated that physical therapists have been under-loading and under-stressing their patients in their use of therapeutic exercise. Fifteen years ago, Donald Chu, PhD, PT, ATC, FNSCA, FAPTA told a group of physical therapists that even though their main therapeutic tool was exercise - the average physical therapist not only didn't know about exercise, they didn't know where to go to learn about exercise. The take home message of both is that what you have called "standard medical care" is ineffective. It is ineffective because those prescribing it don't know about exercise.
Strength training is merely a stimulus, which when applied properly, will produce specific, predictable physical responses and adaptations in human beings. As with most stimuli, a certain threshold stimulus is required before the system will respond in the desired manner. From your question it seems apparent that you are asking if strength training, as athletes perform it, is appropriate for persons with medical conditions (RA). The answer is YES. However, the loads, work periods, rest periods between sets, exercises, and workouts will be different for the person with the chronic disease but the body will still respond as the body was designed to respond to the stimulus.
In strength training there are basically four protocols, each designed to produce specific adaptations within the human body. The four are: Hypertrophy, Basic Strength/Hypertrophy, Pure Strength, and Power. Each protocol has specific loads, sets, repetitions to be performed, and rest periods. Research has demonstrated that strength training is an important therapeutic intervention in most conditions for which therapeutic intervention is prescribed. Recent studies of older individuals have begun to advocate the use of Power training for those individuals. To learn about strength training the three best sources are Essentials of Strength Training and Conditioning (4th Ed. - Human Kinetics), The Science and Practice of Strength Training (2nd Ed. - Human Kinetics), and Designing Resistance Training Programs (2nd Ed. - Human Kinetics).
I would strongly advise you to seek membership in the National Strength and Conditioning Association and the American College of Sports Medicine since these two scientific organizations are at the forefront of the science of exercise as medicine. I have attached a paper on the Scientific History of Strength Training which provides you with the history of the use of strength training in performance enhancement and medicine, as well as an extensive reference list of the subject.
Biggs M, Yap C. The effect of high-intensity strength training as compared to standard medical care on muscle strength, physical function and health status, in patients with Rheumatoid Arthritis Functional Class II (2014). PT Critically Appraised Topics. Paper 44. http://commons.pacificu.edu/cgi/viewcontent.cgi?article=1039&context=ptcats