Spending more time sitting is associated with more signs of depression, according to a new study.
With the pandemic and the lockdowns it caused, more people than ever have been working their jobs from home, while self-isolating. Due to this shift many parts of our day that used to involve physical movement, such as our commutes or hours spent in the gym, have turned into sedentary hours. While unfortunate, this gave a team of researchers at Iowa State University a unique opportunity to study the effects of widespread, sustained sedentarism on public and personal health.
According to the findings, people who maintained a higher proportion of sitting time in their daily lives between April and June 2020 were more likely to have symptoms of depression compared to those who engaged in a more dynamic lifestyle. While the study can't establish a direct causal link between sitting and depression, it does uncover a link that's worth a deeper examination in the future.
Sitting down, feeling down
"Sitting is a sneaky behavior. It's something we do all the time without thinking about it," said Jacob Meyer, assistant professor of kinesiology at Iowa State University and lead author of the paper.
"In March 2020, we knew COVID was going to affect our behavior and what we could do in lots of weird, funky ways that we couldn't predict," he adds.
Meyer and his colleagues at the Wellbeing and Exercise Laboratory at ISU, Trinity College Dublin, University of Dublin, and the University of Limerick examined how physical activity and sedentary behaviors impact mental health. They were also interested in quantifying how changes in these behaviors can influence the way our minds work, our emotional states, and our perceptions of the world around us.
For the study, they surveyed a sample of over 3,000 participants from all 50 U.S. states and the District of Columbia. As part of these surveys, the participants self-reported how much time they spent daily on certain activities including sitting, looking at screens, and exercising. They were also asked to detail how the time spent engaged with each activity and their general behavior revolving around them changed after the onset of the pandemic. Standard clinical scales were included in the surveys through which the participants could indicate changes they observed in their mental wellbeing since the onset of the pandemic.
These activities and the particular mental health markers used in this survey were chosen based on previous research regarding factors affecting mental health.
"We know when people's physical activity and screen time changes, that's related to their mental health in general, but we haven't really seen large population data like this in response to an abrupt change before," Meyer said.
According to the results, participants who met the criteria set out in the U.S. Physical Activity Guidelines before the pandemic, which call for 2.5 to 5 hours of moderate to vigorous physical activity per week, decreased their levels of physical activity by 32% on average after lockdown measures came into effect. These participants further reported feeling more depressed, anxious, and lonely following the change.
A follow-up study from the same team tracked how the participants' behaviors and mental health changed over time by asking them to fill out the same survey once per week between April and June. This study uncovered that people who continued to spend a large part of their time sitting maintained a higher level of depressive symptoms on average compared to everyone else.
"In the second study, we found that on average, people saw their mental health improve over the eight-week period," Meyer said. "People adjusted to life in the pandemic. But for people whose sitting times stayed high, their depressive symptoms, on average, didn't recover in the same way as everyone else's."
Still, the authors underline that an "association" between sitting and depressive symptoms is not the same as saying that one causes the other. It's possible that people who were more depressed simply sat down for longer periods of time, or the people who sat more became depressed from other causes. There could be other factors at play here that the surveys can't account for, as well. But the results warrant further research into the topic, says Meyer.
Changing our habits is very difficult even when we want to do it, the team explains. However, they hope that the current papers will help bring awareness to just how important it is to move, even a little, every day. If you're stuck at home, you can try forming a habit of taking a short walk before and after your workday, for example. This will help alleviate the negative effects of sedetarism and help impart some structure to your day, both of which will be beneficial for your mental health.
The paper "High Sitting Time Is a Behavioral Risk Factor for Blunted Improvement in Depression Across 8 Weeks of the COVID-19 Pandemic in April–May 2020" has been published in the journal Frontiers in Psychiatry.