According to a new study led by researchers at the Iowa State University (ISU), exercising for half an hour may reduce symptoms of depression for at least 75 minutes post-workout and amplify the benefits of therapy.
Professor of kinesiology at ISU, Jacob Meyer said, “A lot of previous research on the effects of exercise on mental health, in general, have used very broad measures of wellbeing. What we were interested in, specifically, is: how does acute exercise — that is, one session of exercise in a day — influence the primary symptoms of depression.”
The researchers recruited 30 adults, for the first study, who were experiencing major depressive episodes. The participants filled out electronic surveys immediately before, half-way-through and after a 30-minute session of either moderate-intensity cycling or sitting, and then 25-, 50-, and 75-minutes post-workout.
Each survey included standard questions and scales used to measure symptoms of depression and several cognitive tasks, including the Stroop test; participants responded to the colour of a particular font rather than the word itself.
The researchers then used the survey data to track any changes in three characteristics of major depressive disorder, depressed mood state (e.g., sad, discouraged, gloomy), anhedonia (i.e., difficulty experiencing pleasure from activities previously enjoyed) and decreased cognitive function (e.g., difficulty thinking, juggling multiple pieces of information at once).
During the cycling experiment, participants' depressed mood state improved over the 30 minutes of exercise and consistently up to 75 minutes afterwards. As for cognitive function, participants who cycled were faster on the Stroop test mid-exercise but relatively slower 25- and 50-minutes post-exercise compared to participants in the resting group. Meyer said more research is needed to understand the variation.
“The cool thing is these benefits to depressed mood state and anhedonia could last beyond 75 minutes. The results suggest a window of time post-exercise when it may be easier or more effective for someone with depression to do something psychologically or cognitively demanding,” Meyer said.
