Biofeedback systems are tools to aid relaxation as opposed to stress management techniques.
Biofeedback systems use electronic sensors to measure stress, and then feed the results of this measurement back to the athlete. This feedback may take the form of movement of a pen on a graph plotter, or maybe by the pitch of sound coming through earphones.
This feedback allows you to experiment with stress management techniques, and actually see, or hear them taking effect on your body. It allows you to practice different ways of using the techniques and compare the results.
There are three main approaches to biofeedback:
Skin temperature methods: adrenaline diverts blood from the body surface to the core of the body, in preparation for response to danger. As less warm blood is going to the surface, skin temperature drops.
Skin electrical activity methods: when you are under stress you sweat more. Skin that is damp (sweating) conducts electricity more effectively than skin that is dry. These methods of biofeedback measure the amount of electricity conducted between two electrodes on the skin.
Muscle electrical activity: these methods measure the electrical activity of muscles under the surface of the skin. This is useful in measuring the tension of these muscles.
Biofeedback methods are useful ways of demonstrating the effectiveness of what may otherwise seem to be fairly nebulous methods of relaxing such as imagery. They convert vague feelings into hard, observable information, and help an athlete to fine-tune the use of stress management techniques.
The stress response:
When you find an event stressful, your body undergoes a series of changes, called the stress response. There are three stages to this response. They are:
Stage 1 - Mobilizing Energy
At first, your body releases adrenaline, your heart beats faster, and you start to breathe more quickly. Both good and bad events can start this reaction: the night before your wedding or the day you lose your job.
Stage 2 - Consuming Energy Stores
If, for some reason, you do not escape from the first stage, your body begins to release stored sugars and fats from its resources. At this stage, you will feel driven, pressured and tired. You may drink more coffee, smoke more, and drink more alcohol than is good for you. You may also experience anxiety, memory loss, catch colds or get the flu more often than normal.
Stage 3 - Draining Energy Stores
If you do not resolve your stress problems, the body's need for energy will become greater than its ability to produce it, and you will become chronically stressed. At this stage, you may experience insomnia, errors in judgment, and personality changes. You may also develop a serious sickness, such as heart disease, ulcers or mental illness.