Directly affecting approximately 10% of the population during their lifetime, major depressive disorder (MDD) causes a significant impact on the individuals affected and their families. Just over half of the people who live with MDD seek assistance, and of those a smaller number receive evidence-based treatment options.
Treatment options for MDD vary, including:
- neurostimulation (electroconvulsive therapy), and
- repetitive transcranial magnetic stimulation
Despite the evidence that these treatment options do work, their suitability for any given individual should be carefully considered due to possible side-effects, cost and accessibility. In addition to these options, alternative economical treatments should be considered.
Exercise and physical activity as an alternative treatment option for MDD has delivered positive outcomes. The American Psychiatric Association has taken to including exercise as a option in it’s most recent guidelines for treatment.
So what do we know about the relationship between exercise and MDD?
Both aerobic exercise and resistance training can be beneficial.
Aerobic exercise is essentially exercise that causes shortness of breath. Running, swimming, cycling and walking are all examples of aerobic exercise that has been shown to be beneficial in reducing symptoms for people with MDD.
Resistance training involves such exercise as lifting weights, walking with hand weights, and other exercise that requires you to ‘work against gravity’ (hence the name resistance). Less research has been conducted with resistance training exercise, however the results suggesting its benefits in reducing the symptoms of depression are optimistic.
How often? Ideally exercise 3 times per week for 45-60 minutes each time.
Recommendations for how often to exercise and duration can vary considerably. The reasons for the variation can be dependent upon the desired outcome of the exercise (for example improving diabetic control, increasing fitness levels, weight-loss). In the instance of reducing symptoms of depression, studies have compared 2-5 sessions per week at 30-60 minutes per session. The guidelines for optimally assisting with depression are to participate for 3 sessions per week for a duration of 45-60 minutes each time.
How hard? What should be the exercise intensity?
How ‘hard’ to exert yourself when exercising is an important consideration when planning an exercise routine. The guidelines for aerobic exercises (walking, swimming, running etc) are based upon your heart rate. Keeping your heart rate elevated within the range of 50-85% of its maximum capabilities.
In a laboratory this is tested by conducting a VO2 max test. A VO2 max test requires a period of time spent on a treadmill or rowing machine with various breathing apparatus attached. Most of us don”t have the opportunity to complete this rather unpleasant task, so as a rough guideline if you subtract your age (in years) from 220, aim to work at 50-85% of this number.
So, a 50 year old person should approximate their maximum heart rate at 170 bpm (beats per minute) and to benefit from the anti-depressant effects of aerobic exercise, be exercising somewhere between 85-145 beats per minute. This is most easily kept track of with a heart rate monitor. However if you want to quickly (and cheaply) gauge your heart rate, simply hold two fingers to your neck or your wrist until you can feel your pulse. Count the number of beats over a 6 second period and add a 0, this will give you an approximation of your heart rate for 60 seconds.
The guidelines for resistance training is to repeat an exercise 8 times, briefly rest and then repeat two more times (resulting in 24 repetitions of the exercise). The weight of the resistance should be 80% of the heaviest weight you can complete by yourself. So, for example if the heaviest single bicep curl you can complete (with good form) is 10kg, then the weight you lift for your 3 sets of 8 repetitions is approximately 8kg.
For how long? Keep exercising for at least 10 weeks.
Some studies have shown significant improvement in depression symptoms in as short as 4 weeks. Most studies are supportive of a continuation of the exercise program for at least 10 weeks. When focusing from a lifestyle perspective, the recommendation would be to make exercise a life-long pursuit. However, from the perspective of reducing depressive symptoms at least 10 weeks is the recommendation.
Can I make it easier to achieve? Using psychology to maintain exercising.
Maintaining an exercise regime is not always easy. Maintaining an exercise regime when you are experiencing depression can be even less so. Understanding some of the factors that help to maintain exercise can help to make the change easier.
Experience tells me that people find it challenging when life feels out of control or unpredictable, it is harder to cope. Engaging in an exercise regime is best assisted when the opportunity of choice is offered. Choosing the type of exercise, the location, and frequency will increase the perceived level of control over the activity and consequently increase involvement and adherence.
Choosing and maintaining an exercise regime can often be challenging initially. For some people, seeking the support of a health professional (such as exercise physiologist or psychologist) may help to overcome some of the barriers to change.
Much of the information included in this blog is based on the meta analysis written by Rethorst and Trivodi on the prescription of exercise for people with a major depressive disorder. A meta-analysis is a research paper that summarises key findings of a multitude of research papers on a particular topic.
Information provided in this piece are general in nature. People experiencing depression should seek advice from their treating professionals to determine the appropriate course of action for themselves. People who have not exercised recently should seek approval by their medical practitioner to commence an exercise program. An exercise physiologist is an appropriately qualified health professional to assist you in planning an exercise program.