Thursday, March 5, 2009

Exercise benefits Quality of Life

You can click on the chart to expand it; the chart above is from a randomized, controlled, 2009 study by CK Martin et al., published in the major journal Archives of Internal Medicine, in which 6 months of regular aerobic exercise is shown to improve numerous domains of quality of life, including mental health, vitality, and social functioning, in a group of 430 sedentary postmenopausal women.

To interpret the chart, look at each symptom domain. There is a control group (which did not exercise), then groups which exercised approximately 1, 2, and 4 hours per week, with the groups which exercised more represented towards the right-hand side of the chart.

The improvement in quality of life did not depend on any weight loss occurring with the exercise. And it appeared that as little as an hour a week of exercise was beneficial, though 2-4 hours per week were slightly more beneficial than just one. Here's a link to the abstract:

As a cautionary note, I find "exercise addiction" to be another potentially serious problem, which could substantially REDUCE quality of life. The above data support a very modest amount of exercise, in the order of 4 hours PER WEEK , for improving quality of life.

I strongly encourage people to exercise. I believe it is basic self-care, a requirement for health.

It is intuitively obvious that exercise would be beneficial for psychological health, and be a good potential therapy for depression or anxiety.

Yet, there is an important recent study of over 5000 Dutch twins, which shows that exercise did not have a direct influence on anxiety or depression. This is a surprising result, but it needs to be taken seriously. Twin studies are very powerful in research, since they look at individuals who are genetically identical -- any differences in symptoms would have to be caused by environmental factors, as opposed to genes. Twins who exercised more than their co-twins were not in fact any less anxious or depressed. (Actually, as I look at the results directly, I see there was a small association, but it was judged to be "non-significant")

The study did confirm that people who exercise are, on average, less anxious and depressed than those who do not exercise. But the conclusion was that this is not because exercise improves emotional symptoms -- it is because there is a genetic factor which predisposes some people both to exercise more, and to have fewer psychological symptoms.

Here is a link to the study:

On the other hand, there are a few studies which show a therapeutic effect of exercise on psychological symptoms:

The above studies show a beneficial effect of exercise, of at least 3 times per week, 30 minutes per session.

Why are there seeming contradictions with these studies?

It may be because the twin study was looking at individuals' intrinsic exercise behaviours, as determined by their life circumstances & inherited factors. Variations in exercise between twins may have been due mainly to opportunity or chance.

The other studies were looking at exercise as a formally prescribed treatment. This would involve a directed change of behaviour, outside of what the individuals would normally do on their own.

It could be that prescribed changes of behaviour, if adhered to for health reasons, could have a stronger therapeutic effect than the behaviours engaged in for other reasons.


Anonymous said...

This is really interesting to me. I think that the most effective non-psychotherapeutic treatment that I have ever had is exercise. Sometimes the immediate effects of exercise seem pretty dramatic to me. I've noticed that the main symptoms that improve are concentration and anxiety (or, specifically, ruminative thoughts, a feeling of being trapped in a kind of mental loop that I can't get out of, etc). But the other things that I've noticed are that 1) only intense, prolonged exercise creates this kind of symptom relief (30 minutes of exercise a day would n't help, it has to be at least an hour or more of intense exercise), and 2) the effects wear off pretty quickly-- i.e., I feel pretty good for a few hours afterwards, but this kind of symptom relief doesn't carry over to the next day. (Or, if there is a kind of prolonged effect on symptoms, I think that it has more to do with an increased sense of mastery, control, etc.-- but, again, I don't think that I would feel this kind of mastery, control etc. with 30 minutes of exercise a day). My point is that I find exercise to be very helpful-- much more helpful than almost anything else I have tried-- yet I don't think that a more moderate approach to exercise, i.e. the kind of exercise regimen that would be "prescribed" by a physician or therapist, would be helpful. I'm going to express this very poorly!-- but I guess I wonder if the biological or neurochemical changes that occur with more intense or prolonged exercise are different from those that occur with more moderate exercise.

GK said...

I think this is very important.

It reminds me of why I think psychotherapy is often not "curative": it is because the intensity and duration is often not sufficient to cause lasting, permanent changes in the brain, unless there are aspects of the therapy that one can practice intensively between appointments.

In this regard it is like language learning (I've often used this comparison before): an immersion experience for a few months is much, much more effective than years of weekly lessons. I think about 1 000 hours of concentrated effort are required for the brain to learn a new fluency, 10 000 hours for the brain to master it. This applies to any skill, whether it be intellectual, technical, mechanical, or psychological (e.g. learning techniques to attain emotional calm).

The brain can change radically, but the level of effort and time required can be very high.

Anxiety symptoms can be extremely powerful, like a high wall that keeps one trapped. Extreme, prolonged efforts may help get past this type of wall for brief periods of time.

I think it is important to keep and nurture those activities that you have discovered within yourself to provide even momentary relief or satisfaction, provided they are not doing harm to your body or mind.

I'm interested in finding other forms of therapeutic "immersion" that could also help--to see if there are numerous pathways that could be found over the anxiety "wall", perhaps strategies that would eventually cause the whole wall to disintegrate. I'm convinced it's possible.