News & Insights 10 September 2020

The link between sedentary time and depression

Recent articles published in the Daily Mail, Medical News Today and Stylist Magazine have picked up on an interesting study which looked at the relationship between sedentary time during childhood and the risk of depression in adolescence. Whilst the link between physical activity and improved mental health is well established, the extent to which large periods of daily sedentary time can contribute to poor mental health, in this case being the risk of experiencing symptoms of depression, is yet to be fully documented.

Much of the pre-existing research has focussed on the benefits of participating in moderate to vigorous intensity physical activity, and resultantly disregards the benefits of light intensity activity, despite the fact that this lighter dimension of activity is far more accessible to people from all walks of life. Whilst the aforementioned researchers attempted to fill this gap within the literature, they similarly sought to address the lack of research surrounding younger populations. Previous studies have primarily examined the link between physical activity and depression in adults, despite the fact that almost half of all mental health conditions begin to develop before age 14.

This new study followed 4257 individuals, tracking their physical activity levels using hip-worn accelerometers over a 7-day period at 3 different time points – age 12, 14 and 16. The use of body mounted accelerometers to collect physical activity data eliminates the bias often associated with self-reported measures of physical activity. Depressive symptoms were assessed when the participants were around 18 years of age using the Clinical Interview Scheduled-Revised (CIS-R) questionnaire. The researchers found that for every additional hour of daily sedentary behaviour, there was an associated 8.0-11.1% increase in the risk of suffering from symptoms of depression at age 18.

Another notable outcome from the study was that light intensity activity appeared to offset the negative effects of sedentary time, with every additional hour of daily light activity reducing the risk of suffering from depressive symptoms at age 18 by 7.8-11.1%. This may seem fairly obvious given that you are replacing sedentary time with activity, however it is the nature of this activity – the lighter intensity – which makes it appear far more accessible and achievable for all demographics. This is because it’s possible to accumulate significant levels of light activity without putting too much thought into it. Even the most mundane of tasks such as cooking, cleaning, household chores or gardening are often enough to count as light intensity activity, meaning it shouldn’t be too challenging to increase the amount you do on a daily basis. As mentioned previously, much of the research has focussed on physical activity of higher intensities, so it is welcoming to see a study add to the evidence base surrounding the benefits of light intensity activity.

At KiActiv® we know that physical activity is multi-dimensional, so new research underlining the value of physical activity across different dimensions is very positive. We are re-establishing an understanding of everyday physical activity for health, and shifting the narrative away from just ‘sport and exercise’ enables these health benefits to be felt by many more people. Our online mentor-supported programme is tailored to the specific needs of each individual and we can help you develop a personalised understanding of your own physical activity, what it means for you and how you can go about making improvements that are both good for your health and fit realistically with your current lifestyle.

The KiActiv® Team