Continuum

It's not only the title of you favourite Canadian produced sci-fi tv show, but its also the healthy state of your tissues. 

Don't go too far right - Adapted from my favourite review article - How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury

The cells, tissues and systems of your body exist on a continuous pathway of healthy states and unhealthy states. Exercise is normal stressor when applied properly and when allowing for proper recovery which includes nutrition,sleep, low psychological stress. A healthy balanced training regime, or recovery from injury and illness will be based on some periods of challenge and periods of reprieve. It's kind of like the tide, or how seasons change, or why your favourite Baseball pitcher can only throw so many pitches in a game.