16. Use it or lose it (i.e. keep exercising)

Our modernity with its great depth of physical comfort is kind of killing us softly. In general, our bodies are designed for sustained heavy work. Think about how much you can sweat. This is the developed interrelationship of the need for active muscles. The sweat carries away the heat generated by the strongly working muscles. Those muscles need to be used to maintain them. With the loss of sufficient muscle mass your body biochemistry and physiology begin to lose the necessary feedback to function properly and disease begins to creep into your life, lessening its quality. It doesn’t need to be exercise, even something that implies an unusual effort, just use it.