A recent survey published by the Mental Health Foundation found that 59% of British adults felt their life was more stressful than it was five years ago. 47% of all survey respondents said they felt stressed every day and a further 24% said they felt stressed every few days. The Health and Social Care Information Centre also recently published data which showed hospital admissions for stress have risen by 7% in just 12 months, and the Health and Safety Executive recently published figures which indicate a rise in sick days due to work-related stress.
Stress causes the body to produce more of the so-called ‘fight or flight’ chemicals which prepare it for an emergency. Adrenaline and noradrenaline raise blood pressure, and increase heart rate and perspiration. They can also reduce blood flow to the skin and reduce stomach activity. The body produces cortisol which in turn causes fat and sugar to be released into the bloodstream (but also reduces the efficiency of the immune system). All these changes are the body’s way of making it easier to fight or run away. Unfortunately these changes are less helpful for individuals stuck in a busy office or on an overcrowded train. They cannot fight and cannot run away. Because of this, they cannot use up the chemicals their own bodies have produced to protect them. Over time these chemicals and the changes they produce can cause serious damage to health. For example, people suffering from stress may start to experience headaches, nausea and indigestion. They may breathe more quickly, perspire more, have palpitations or suffer from various aches and pains. Longer term stress can lead to feelings of strain, worry, insomnia and exhaustion, and increased risk for health problems such as heart attacks and strokes.
The Mental Health Foundation survey found that 18% of people found drinking alcohol helpful for stress and 10% found smoking helpful, while only 6% would consider visiting a GP. This is worrying because in the long run alcohol and smoking can make mental and physical health problems worse.
Physical activity may offer an alternative approach to reducing or managing stress. Cross-sectional studies on adults who are employed have found that highly active individuals tend to have lower stress rates compared to low active individuals. Several mechanisms have been suggested to explain how physical activity may reduce the harmful effects of stress. These include that physical activity enhances mood due to distraction from worries or biochemical changes or increases positive health behaviours during periods of stress (i.e. decreased smoking and healthier eating habits). It has also been suggested that the higher levels of fitness brought about by physical activity result in a more efficient stress regulation (i.e. reduced secretion of hormones, lowered blood pressure) or enhanced recovery from stress.
After considering the evidence from the 31 studies in depth, the authors were confident to advertise physical activity as a stress-management strategy. Furthermore, they found that even though physical activity may not always reduce stress, there was no evidence that engaging in physical activity during periods of high stress increased stress levels, and that physical activity had direct health benefits.