Exercise is the most powerful medicine in the world.
This is an extraordinary claim, but in 2016 I believe it is an entirely supportable one. No pharmaceutical or procedure provided by the modern medical model imposes such a profound healthy stimulus on so many tissues, organ systems, and disease processes as physical activity. The evidence for the manifold benefits of exercise has become simply overwhelming. The result has been a growing call for doctors and patients to recognize that, as the title of a paper in the British Medical Journal proclaimed, Exercise is Medicine and Doctors Should Prescribe It.
But we don't. Not really. And that's because most of us don't know how.
It's not enough to tell our patients to "just get some exercise." Or "go for a walk every day." Or, for heaven's sake, to "lift light weights for a lot of repetitions." These "prescriptions" don't comport with the way we approach the prescription of pharmaceuticals, therapies, or procedures, and they ignore what we know about the effects of different forms of exercises on different populations. They aren't prescriptions at all.
When we prescribe a medicine, we need to be a bit more perspicuous and precise. A proper prescription for any medicine must specify the formulation, route of administration, dose, frequency, and ideally the therapeutic targets and duration of that medicine.
Strangely enough, a proper training program (as opposed to merely exercising) specifies exactly the same parameters. A proper training program specifies exercise selection (formulation and route), loading and volume (dose), frequency (training days) and therapeutic targets (performance and body composition goals).
When it comes to exercise medicine, the prescription is a program. Anything less will not do.
For much more on this, I invite you to take a look/listen at this presentation I gave to the Mid-Michigan Medical Society in January. A bunch of eminences grises in white coats actually invited me to come talk to them about training. I like to think it's progress.