Healthy exercise which increases our physical capabilities is a good stress. Continuous hard exercise without rest or adequate nutrition can become a destructive force with negative effects on our health, our families and our lives. We may be stressed by noises, confined spaces, extremes in weather and other aspects of our environment. In our social environment, conflicts within a group, conflicts with our boss or our family are all stressors. We're also stressed by inactivity and boredom.
Stress produces intricate biochemical changes in the body.
The brain becomes more active, chemicals secreted by the endocrine system cause muscles to tighten, pupils to dilate and heart rate, breathing rate and blood pressure to increase. Protein, glucose and antibody levels in the blood rise. These physiological changes prepare us to meet challenge by making us more alert and ready for physical activity. In the short term they can be helpful. In the long term or if the short-term stress is significant, the effects of stress can adversely affect our physical and psychological health by wearing us down and making us susceptible to a variety of physical and psychological problems.