How 20 minutes of daily exercise reduces risk of depression in older adults

Analysis: research finds older Irish adults who exercised had a 16% lower risk of depressive symptoms and 43% lower odds of major depression

By Eamon J. Laird and Matthew P. Herring, University of Limerick

Depression is unfortunately increasingly common among adults aged over 50 years of age and recent research reported a worldwide prevalence of nearly 30%. Depression is an important risk factor for and comorbid condition of the major chronic disease conditions, including cognitive decline, cardiovascular disease and chronic pain, and increased risk of mortality and suicide. Depression causes over 5 to 10% of the burden of all diseases in Europe and the economic cost in the United States alone is estimated to be over $210.5 billion.

Given the enormous health and social costs, potentially easy and low-cost health and lifestyle solutions that could reduce the risk of depression, especially among those with chronic disease, are of clear interest. Recent research has shown moderate-to-vigorous intensity physical activity was linked with benefits for depression. This is activity that can cause someone to be out of breath, such as brisk walking).

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

From RTÉ Radio 1's Drivetime, Dr Eamon Laird from University of Limerick on research finding a link between exercise and lower risk of depression

However, there is no agreement on how much physical activity is protective which is particularly important for older adults who may find physical activity difficult. Therefore, identifying the minimal amount of activity for protection against depression is extremely valuable.

In our research, we investigated over 4,000 older adults from The Irish Longitudinal Study on Ageing. This is a large population representative study of community-dwelling older adults living in the Republic of Ireland. We used 10 years of data from 2009 to 2018 (Waves 1-5) with each Wave containing the same people followed up across time.

We measured depressive symptoms and Major Depression status (presence or absence of Major Depression) at every collection point, along with information including gender, educational attainment, smoking, alcohol use, obesity, if they had a chronic disease and if they used anti-depressants. For physical activity, we used a questionnaire to collect information and classified activity into five different 'dose' categories – zero/no reported activity, not meeting current recommendations, meeting current recommendations, exceeding current recommendations, and the highest doses of activity.

We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences

From RTÉ Radio 1's Today With Claire Byrne, what is your biological age?

When we analysed all the information, we found that older adults who did the equivalent of 100 minutes of moderate-intensity activity per week, such as 20 minutes per day five days a week, had a 16% lower risk of depressive symptoms and 43% lower odds of Major Depression over the ten-year period. This was the lowest dose where we observed benefits for depression. Importantly, the more minutes of activity, or higher overall dose, the greater the benefits. Other factors that also influenced depression included female sex, a lower education level, smoking, alcohol use and antidepressant use.

Can we explain the mechanisms?

Physical activity can have wide ranging benefits for health from improving immune and metabolic function, enhancing blood flow to the brain, along with effects on neuroendocrine factors and other biological systems which affect brain health. Regular activity in the form of exercise training can also have many psychological and emotional benefits, including more social interactions, increased confidence, distraction from worries, and as a coping mechanism for stress.

What do these findings mean?

Overall, our work suggests that performing physical activity that is at least moderate-intensity (e.g. brisk walking) could reduce the risk of depressive symptoms and Major Depression among older adults. These findings are consistent with calls for a ‘lifestyle medicine’ approach to depression prevention and management involving combinations of education on healthy lifestyle choices, achievable physical activity, sleep, and healthy eating, which could benefit both general and mental health.

Try and not think of activity as a mandatory uncomfortable chore

How to get started and keep motivated

Try and think about the type of activities you enjoy and also when and how they could be done every day. For example, is it easier to go for a brisk walk or a jog in the morning or evening? Do you have a weekly activity to do with friends that can be set?

Try and not think of activity as a mandatory uncomfortable chore! It has to be something that is enjoyable and easy to build into your lifestyle to make it sustainable and long-term

Try and set achievable targets and figure out what barriers might be in the way and a solution to overcome them. If you are starting off from scratch, it is better to start off slow -think realistically about what you may be able to do and your own abilities. If you are worried about going outside there are many activities that can safely be done in your home or garden whilst you can always exercise with friends, family or grandchildren.

Dr. Eamon J. Laird is a researcher at the Health Research Institute at the University of Limerick. Dr. Matthew P. Herring is a Lecturer in Sport, Exercise, and Performance Psychology in the Department of Physical Education and Sport Science within the Faculty of Education and Health Sciences and Director of the Exercise is Medicine Ireland National Centre at the University of Limerick.

The views expressed here are those of the author and do not represent or reflect the views of RTÉ