Exercise as it relates to Disease/Exercise as a tool in preventing depression
Regular exercise and physical activity plays a vital role in preventing a wide range of lifestyle-related diseases. Depression is a serious mental illness that constitutes a state of low mood and aversion to activity that can affect a person’s thoughts, behaviour, feelings and sense of well-being.  No one is immune to depression and approximately 1 out of 5 people suffer from the illness at some point in their lives.  The World Health Organization estimates that depression and depression related illnesses will become the greatest source of ill health by 2020. 
Signs and Symptoms
Signs and symptoms of depression vary between individuals as depression affects each person differently. However, some common symptoms that could potentially result in depression include:
• Lowering of mood
• Loss of confidence, appetite and sex drive
• Lack of interest and persistent negativity and cynicism
• Lack of motivation
• Low levels of energy and poor concentration
• Interrupted sleep patterns
Exercise Used to Prevent Depression
There is increasing evidence to support the idea that physical exercise is an effective method for preventing depression, with studies portraying a decrease in signs and symptoms in participants who are physically active.
How it Works
• Leads to the release of certain neurotransmitters in the brain that alleviate pain, both physical and mental. 
• Increases storage and information processing within the brain
• Initiates neurogenesis- The creation of new neurons
• Regulates mood- Elevates mood status
• Improves self confidence
• Regular exercise increases serotonin levels
• Increases life expectancy- Through encouraging a healthy lifestyle
• Improves concentration and cognitive functionality 
There is no specific exercise program to assist in the prevention of depression, however research indicates that mental health can be improved by low to moderate physical activity. It is important to have an individualised exercise program specific to the individuals ability and needs, however some common guidelines include:
|Frequency||3-5 times a week|
|Intensity||low to moderate|
|Time||30+ minutes a day overall|
The National Physical Activity Guidelines for Australians
• A minimum of 30 minutes of moderate intensity exercise on most, preferably all, days of the week (an example of ‘moderate intensity’ exercise is brisk walking where you notice a slight increase in breathing and heart rate).
• Exercising for at least 10 minutes at a time - the 30-minutes total does not need to be continuous you can combine short sessions of different activities to a total of 30 minutes or more each day.
• Being active in as many ways you can each day (e.g. use the stairs).
• Both aerobic exercise (e.g. brisk walking, cycling or jogging) and resistance or strength training (e.g. weight-lifting) have been found to be beneficial for depression. 
Other Factors in Need of Consideration when Developing a Program
• Objectives of exercise program need to be realistic- unrealistic objectives can cause individuals to give up and stop exercising because of failed attempts.
• Program must be appropriate to ones fitness level- unrealistic training regimes can discourage individuals to participate in physical activity and can increase feelings of self-worthlessness.
• Participate in physical activity the individual enjoys- Team orientated or individual based physical activity depends on the individual
• Exercise program needs to be fun and interesting
- Salmans, S (1997). Depression: Questions You Have – Answers You Need. People's Medical Society. ISBN 978-1-882606-14-6.
- Hotopf, M (2002). Depression in advanced disease: a Systematic review part 1. Prevalence and case finding. Vol. 16 pp 81-97
- Pretty, J., Peacock, J., Sellens, M., and Griffin, M., (2005). ‘The mental and physical health outcomes of green exercise’, International Journal of Environmental Health Research, Vol. 15, no 5, pp. 319-337
- Welch, L. (2011). Fight depression with exercise Fawshaw Focus. Vol. 7 pp 4
- DepressioNet.org.au (2011). What is depression. Information, help and support for 'people like us', Australians living with depression. http://depressionet.org.au/what-is-depression/
- McGovern, M. (2005). 'The effects of exercise on the brain'. Biology 202, Serendip.
- Daley, A. (2002). 'Exercise therapy and mental health in clinical populations: Is exercise therapy a worthwhile intervention?' Advances in Psychiatric treatment. Vol. 8. pp 262-270
- Westerner, S., Kupfer, B. (1994). 'Physical exercise and psychological health'. Sports Med. Vol. 17. pp 108-116
- Black Dog Institute Australia. (2011). Exercise and depression. http://www.blackdoginstitute.org.au/docs/ExerciseandDepression.pdf
- Francis, J. (2010)'The role of depression in short-term mood and fatigue responses to acute exercise'. International Journal of Behavoural Medicine.