Good Medicine

In an excellent article, The underappreciated role of muscle in health and disease, Robert Wolfe has this to say:

"There is little debate regarding the beneficial effects of exercise on muscle, whether it be to maintain or attempt to restore muscle mass and function. The most practical issue from a public health standpoint is motivation. In that light, it is important to identify the minimal exercise regimen to achieve desired results, including maximizing the interactive effects between nutritional intake and exercise on protein synthesis. Furthermore, the desired result should be identified in terms of outcomes on muscle mass, strength, and metabolic function, as opposed to traditional measures of exercise training, such as the maximal oxygen consumption, which have little direct relation to health outcomes."

In other words, exercise is physcial medicine. Like any medicine, it must be dosed appropriately. You need the right amount and the right type to produce the desired result. As the above quote makes plainly clear, the desired result is to build muscle. Muscle is the only system in your body that you can directly exercise. Other changes, such as increased bone density or improved cardiovascular efficiency occur secondarily to work performed by the muscles. If you are going to bother with exercise, you should ensure that your work produces some kind of positive adaptive change in your muscular system. You should get stronger. And the best way to do that is to strength train.