A concept I've borrowed from Hans Selye, the Canadian stress researcher, is his idea of life force energy. I believe that he means there is a source of energy that comes from within every living body. However, this source of energy is finite in that just so much of it is available to us, and when we use it up we get very sick, often give up and die.
I don't know the actual chemistry of this energy. I only know I've experienced it when I have pushed myself too hard for too long a time and I have had to reach down inside me and steel myself to do the task at hand. Apparently, we can only reach down and use this life force energy so many times before it gets depleted and we get sick.
I believe we need to establish a way of life that assists us in producing energy, a lifestyle that creates energy, passion and purpose for life, so we don't have to use the body's life force energy for daily living. We need the life force energy to fight off disease, tragedy, and extreme stress. The life force energy is definitely not to be used for daily living.
A healthy lifestyle is much like the alternator of a car. The alternator provides the energy to produce the spark to drive the pistons on a regular basis. The battery is used only for one moment to start the car. Once the engine is started, the alternator is responsible for the energy to continue driving the engine.
So it is with a properly balanced lifestyle. Only occasionally should the body dip into its life force energy, because the way the person has chosen to live life produces the excitement, purpose and passion - in essence, the energy - to drive that person. Often I hear people saying they wish they had more energy. To have more energy and pour it into a lifestyle that is without balance is to waste that energy believe what they need is a lifestyle overhaul.
Examining and overhauling your own lifestyle as often as you have your car checked would be intelligent maintenance.
Tension robs the body of energy. Relaxation allows the body to make available energy at a high rate for an extended period of time.
You once knew how to relax. You grew up and trained your body how to speed up. Now it's time to change back. Revert! Retrain! Relax!