As I navigate the stresses and joys of raising three children and running a business, I realize over and over how difficult it would be to cope without my workouts.  Exercise lends a structure and sustenance to my life that is almost beyond words.  After I run or cycle, difficult issues become manageable and sadness is abated.  Please keep in mind that I became active as an adult after a decidedly non-athletic childhood. The notion that depression was not a purely psychological disorder emerged in the 1950s, when the first antidepressant drug was discovered.  What was the original intended use for this first medical treatment for depression? It was a tuberculosis drug that made people “inappropriately happy”!  Then, a new antihistamine medication produced similar mood-elevating effects, giving birth to a new class of drugs called tricyclic antidepressants.  This led to a search for how the brain influences the mind, and rendered obsolete the concept of depression as “psychological weakness”. It is largely through depression research that we know as much as we do about how aerobic exercise impacts on the brain.  Cardiovascular exercise, in fact, counteracts depression at almost every level. The statistics on depression are a wake up call to action – according to the World Health Organization, depression is the leading cause of disability in the United States and Canada, ahead of coronary heart disease, any cancer, and AIDS.  About 17 percent of adults experience depression at some point in their lives.  Depression often co-occurs with anxiety disorders and substance abuse.  

• One twenty-year longitudinal study of 8023 people found that inactive individuals were 1.5 times more likely to experience depression that active individuals.
• A massive Dutch study of 19,288 twins and their families published in 2006 showed that exercisers are less anxious, less depressed, less neurotic, and also more socially outgoing.
• A Finnish study of 3403 people in 1999 demonstrated that those who exercise at least two to three times a week experience significantly less depression, anger, stress, and “cynical distrust” than those who exercise less or not at all.
• An epidemiological study from Columbia University from 2003 of 8098 people found the same inverse relationship between exercise and depression.

In Britain, doctors now use exercise as a first-line treatment for depression, but it is vastly underutilized in North America.  Medication is often a critical part of any treatment plan, but unfortunately medication does not work for everyone.  In addition, there can be unpleasant side-effects that deter some patients from continuing with drug treatment.  If you suspect you are suffering from depression, you must consult your doctor to establish a treatment plan that is appropriate for you, that may include both medication and physical activity! References

• Ratey, J. (2008).  Spark: The Revolutionary New Science of Exercise and the Brain.  New York: Little, Brown and Company.
• World Health Organization (WHO): Depression.

Exercise Specialist Recommendations So, have I convinced you yet?  Exercise can mitigate and prevent depression – so get moving!  The following recommendations are evidence-based, grounded in recent research on what we call the “dose-response ratio”:

• Exercise 3-5 times per week for about one hour.  A higher weekly caloric expenditure (how many calories you burn) is positively correlated with better management of depression symptoms.
• Exercise at a moderate to high intensity (a stroll around the neighbourhood may be pleasant, but will probably not impact on depression – powerwalking is better).  Research shows that low intensity cardiovascular exercise was only as effective as a placebo.
• Increase intensity slowly over 6-12 weeks, to prevent injuries that can sideline your efforts.  Consult a qualified trainer for help on how to do this, as it is both an art and a science.
• Download your favourite music/podcasts/books on tape onto your ipod and listen as you sweat.  Transform your workouts into rewarding time for yourself, as opposed to a punishment or a dreaded task.
• Whenever possible, exercise first thing in the morning – which increases adherence.  Seventy-five percent of people who exercise in the morning stay with it, as opposed to 25 percent of evening exercisers.  That being said, do what works best for your schedule.
• Schedule your workouts into your planner as appointments that cannot be cancelled.  Tell anyone who wants to meet with you during that time that you are unavailable, or already have a meeting booked.
• Remember that most people, barring very complex mental health issues I have not discussed (bipolar disorder, schizophrenia, and so forth – exercise may also work for these conditions but at the moment there is little research), can feel healthier, more positive, more energetic, and happier, by harnessing the power of physical activity.

Have fun!  And remember that exercise becomes more enjoyable as you attain a higher level of fitness.