Your body is a beautifully evolved sporting machine, comprising, among other things, muscles that can be trained to a peak of fitness and nerves that control the muscles. The nerves are massively linked in your brain: vast numbers of nerve cells are linked with a hugely greater number of interconnections.
Part of the reason that human children take so long to reach maturity relative to animals is that we have many more nerve cells in our brain. Initially our brains are very disorganised. Much of the process of growing up, being educated, and becoming mentally mature is the process of organising the vast chaos of the interconnectedness of the nerves in our brain into useful pathways.
Much of the process of learning and improving sporting reflexes and skills is the laying down, modification, and strengthening of nerve pathways in our body and brains. Some of these nerve pathways lie outside out brain in nerves of the body and spine. These need to be trained by physical training.
Many of the pathways, however, lie within the brain. These pathways can be effectively trained by the use of mental techniques such as imagery and simulation. These are explained below.
Imagery rests on the important principle that you can exercise these parts of your brain with inputs from your imagination rather that from your senses: the parts of the brain that you train with imagery experience imagined and real inputs similarly, with the real inputs being merely more vividly experienced.
So in its least effective form you can use imagery merely as a substitute for real practice to train the parts of your mind that it can reach. Even at this inferior level of use imagery is useful training where:
Imagery can also be used to affect some aspects of the 'involuntary' responses of your body such as releases of adrenaline. This is most highly developed in Eastern mystics, who use imagery in a highly effective way to significantly reduce e.g. heart beat rate or oxygen consumption.
Simulation, however, is carried out by making the your physical training circumstances as similar as possible to the 'real thing' - for example by bringing in crowds of spectators, by having performances judged, or by inviting press to a training session.
In many ways simulation is superior to imagery in training, as the stresses introduced are often more vivid because they exist in reality. However simulation requires much greater resources of time and effort to set up and implement, and necessarily is less flexible in terms of the range of eventualities that can be practised for.
You should therefore use simulation and imagery together for maximum effect.
The following sections will explain Imagery and Simulation in more detail.