The benefits of exercise on your mental health are well documented, but you don’t have to go overboard – even a little exercise can reduce depression symptoms greatly, new research has found.
Depression, a pervasive mental illness typified by a profound sense of despair, emptiness, or the inability to derive pleasure from life, afflicts approximately 5 per cent of the global population.
Treatments for depression vary greatly, but may include antidepressant medication, psychotherapy or a combination of the two. Exercise will also often be prescribed for depression, but exactly how much exercise do you need to feel its positive effects?
It turns out, not that much.
A long-term, large-scale study conducted by the Health Research Board (HRB) Ireland has determined that as little as 20 minutes of brisk walking, five days a week is enough to reduce depressive symptoms in people aged 50 and over.
Dr Eamon Laird, lead author of the study, told Medical News Today it was the link between depression and late-life outcomes that drove his team towards this experiment.
“Depression is unfortunately increasingly prevalent in the older adult population and is associated with increased risk of chronic conditions including cardiovascular disease (CVD), cognitive decline, mortality, and suicide,” he says.
“Physical activity has been previously shown to be associated with reduced risk of depression; however, no-one has yet investigated what is the bare minimal dose of physical activity that might provide benefits.”
The study looked at 4016 participants from The Irish Longitudinal Study on Ageing (TILDA), a large-scale, longitudinal study that aims to improve the ageing experience of people in Ireland. They collected data at five time intervals between October 2009 and December 2018.
At each time point, the researchers collected detailed information on demographic, health, lifestyle, and social factors through either a self-completed questionnaire, nurse health assessment, or interview.
They assessed depressive symptoms using a short form of the Center for Epidemiological Studies Depression (CES-D). From this definition, they classified major depression as either a CES-D score greater than or equal to nine and/or a major depressive episode at any of the data collection time points.
At each data point, participants self-reported their physical activity for the previous seven days. The researchers then estimated the total number of metabolic equivalent of task (MET) minutes per week for each individual, and categorised them into low, moderate, or high physical activity.
Across all three exercise categories, researchers saw an increase in benefit as their exercise level increased. Individuals taking the most exercise were 20 per cent less likely to experience depression than those in the low exercise category.
But even people taking only a minimal amount of exercise were 16 per cent less likely to experience depression than those who took no exercise.
“Twenty minutes was the minimal dose but we also observed that the greater the level of activity the greater the mental health benefits,” Dr Laird added.
How much exercise do you do each week? Could you manage 20 minutes, five times a week? Let us know in the comments section below.
Also read: When exercise can actually be bad for you