Rejuvenation is the other essential element of recovery. But it can only make you as youthful as you were yesterday. You cannot improve your youthfulness without knowing when and how to rest. The more work you do, and the more intense it is, the more time you need to take to rejuvenate. For example, sprinters who run 100 yards in 10 seconds may need 8 minutes to fully recover for the next race, whereas the same runners, warming up and completing 100 yards in 15 seconds, may need only 3 minutes to fully recover. This principle applies to performers of any kind. For example, pianists cannot practice indefinitely for a recital. They need to know when to rest and for how long.
In fact, everyone is a performer. To be alive is to perform. But if we work too much and rest too little, we exhaust ourselves; and if we work too little and rest too much, we deteriorate. The question is, how do you know how much to perform and how much to rest? The easiest way is to observe how you feel when you wake up in the morning. If you get out of bed feeling excited about the day and eager to accomplish things, you are fine. But if you get out of bed without enthusiasm and energy for the day, your life is out of balance. So the key to rejuvenation is how you feel first thing in the morning.
Athletes have coaches, but everyone else must be his or her own coach. The Happy Body program teaches you all you need to know to be your own coach.