The replacement of ageing and dead cells, and the mending of muscle and other tissue.

    The lowering of energy consumption.

    The recharging of the brain.

 

Rest is one of the most important principles of exercise and often the most overlooked. When you sleep, your body goes into a suspended state of animation, and does precisely what you've been beseeching it to do ever since you raised that first dumbbell: build muscle. If you've just started lifting, give your body parts at least 48 hours to recover between workouts.

 

All mammals, birds and fish observe a regular state of natural rest. The role of sleep in health and disease is increasingly being studied in specialized sleep laboratories throughout the world. Restorative theories of sleep describe it as a time of healing and growth for organisms. Non-REM sleep is an anabolic situation marked by physiological processes of growth and rejuvenation of the organism's immune, nervous, muscular and skeletal systems.

 

Sleep is perhaps best described as the loss of awareness of what is going on around us. Public awareness of fitness and nutrition has grown over the last few years but sadly little is known about the very important subject of sleep disorders. Why do we suffer with sleep deprivation? Stress and anxiety is a major cause, and also a vicious cycle: while stress can actually cause our lack of sleep, it is also a result of it.

 

Animal studies have revealed that sleep is essential for survival. The usual lifetime of rats is 2-3 years. However, rats deprived of sleep live only for about 3 weeks. It has been confirmed that the metabolic activity of the human brain declines considerably after 24 hours of sustained wakefulness. Sleep is required for our nervous systems to work right. Deep sleep is also necessary for the release of growth hormone in children and young adults.