49 studies have previously indicated that exercise confers 'protection' against depression. Today's research analysed all of the studies and found doing exercise gives you up to 31 percent more protection - but does it?
An analysis of every study undertaken to measure the impact of exercise on depression has revealed that researchers have never asked whether people get depressed because they don’t exercise, or whether they give up exercise because they’re depressed.
Analysis from King’s College London published in the American Psychiatric Journal today supports the notion that physical activity can confer protection against the emergence of depression.
Researchers looked at all the global data associated with the 266,939 participants who have been monitored in studies carried out across the world.
Participating in 150 minutes of physical activity over the course of a week led to 22-31 percent higher protection against depression than those who stopped doing exercise, it was found.
However, losing interest in things you previously enjoyed is one of the hallmarks of nearly all clinical tests for depression.
“There is a paradox yes, because the studies didn’t look into whether people had stopped exercising because they were depressed or were depressed because they had stopped exercising,” Dr Brendon Stubbs of the Institute of Psychiatry, Psychology & Neuroscience, King's College London, told Mental Health Today.
“We only followed people who were free from depression at the time research started,” Dr Stubbs added.
“A number of small studies have indicated that exercise confers protection against depression. This brings together all of the studies.”
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49 studies have tested the notion previously but until today no cumulative analysis (meta-analysis) had been applied.
“Those who engage in the highest level of exercise are 15 percent less likely to suffer from depression than others,” said Dr Stubbs, who is also Head of Physiotherapy at South London and Maudsley NHS Foundation Trust.
“150 minutes over the course of a week led to 22-31 percent higher protection against depression than those who stopped doing exercise.”
Holistic policy making
In parliament today, Luciana Berger will introduce a Bill supporting ‘health in all policies’.
The bill is entitled the Health Impacts (Public Sector Duty) Bill and places "a statutory duty on all public authorities to assess the impact of their actions on mental and physical health".
The Labour MP says the building of new housing estates, for example, should encourage walking, cycling or sport.
"It is simply unsustainable to expect the cash-strapped NHS to tackle huge social issues," she said.
"We need every government department, agency and local authority to put people’s health first, and use their collective power to take decisions which improve our mental and physical health."