Our mental games expend a lot of energy and cause us great fatigue, starting in the brain and experienced in the physical body. This information age compounds the problem. Instant everything makes us reach for more and try to do more thus the problems in the mind causing the fatigue are accelerated. We have to unplug, balance the hemispheres of the brain and find our own rhythm. Rhythm creates a quantum effect.
Yoga Set: For Left and Right Hemispheres of The Brain - from Owner's Manual for The Human Body
Meditation: Kriya For Developing Self-Rhythm - From Prana, Pranee, Pranayam manual