Participants in both studies exercised for 30 minutes at a moderate-intensity pace. bigger picture. Photo courtesy of ISU Recreation Services.
AMES, IA – Exercising for half an hour can reduce symptoms of depression for at least 75 minutes after exercise and amplify the benefits of therapy, according to two new studies led by researchers at Iowa State University.
“Much previous research on the effects of exercise on mental health has, in general, used very broad measures of well-being. Specifically, what we were interested in was how acute exercise, that is, one exercise session in one day, influences primary symptoms of depression,” said Jacob Meyer, professor of kinesiology at ISU and lead author of both publications. .
For him first study, the researchers recruited 30 adults who were experiencing major depressive episodes. Participants completed electronic surveys immediately before, midway through, and after a 30-minute session of moderate-intensity cycling or sitting, and then 25, 50, and 75 minutes after training. Those who rode a bike during the first visit to the lab returned a week later to do the experiment again with 30 minutes sitting, and vice versa.
Each survey included standard questions and scales used to measure symptoms of depression and various cognitive tasks, including the Stroop test; participants responded to the color of a particular font rather than the word itself (for example, indicating red when they saw the word ‘blue’ in red ink).
The researchers then used the survey data to track any changes in three characteristics of major depressive disorder: depressed mood (eg, sad, dejected, melancholic), anhedonia (i.e., difficulty experiencing pleasure in activities previously enjoyed) and decreased cognitive function (eg, difficulty thinking, juggling multiple pieces of information at once).
During the cycling experiment, the participants’ depressed mood improved during the 30 minutes of exercise and steadily for up to 75 minutes afterward. The improvement in anhedonia began to decline 75 minutes after exercise, but it was still better than the anhedonia levels of participants in the non-exercising group.
Regarding cognitive function, participants who rode the bicycle were faster on the Stroop test at mid-exercise, but relatively slower 25 and 50 minutes after exercise compared to participants in the rest group. Meyer said more research is needed to understand the variation.
“The good thing is that these benefits for depressed mood and anhedonia could last longer than 75 minutes. We would need to do a longer study to determine when they start to decline, but the results suggest a window of time after exercise when it may be easier or more effective for someone with depression to do something psychologically or cognitively demanding,” Meyer said. .
He said that could include giving a presentation, taking a test or going to therapy.
“Can we combine the short-term benefits that we know to occur with exercise and the clear long-term benefits with therapy to provide the most effective overall intervention?” Mayer asked.
As part of the effort to answer that question, Meyer and his research team conducted a separate study pilot study.
Half of the 10 participants exercised on their own (eg, biked, jogged, walked) for 30 minutes at what they considered a moderate-intensity pace, which the researchers also verified with Fitbit data, before starting session in one hour of virtual cognitive behavioral therapy each. week. The other participants simply went about their daily activities before their therapy sessions.
At the end of the eight-week intervention program, participants in both groups showed improvements, but those who exercised before speaking with a therapist had more pronounced reductions in depression symptoms.
The researchers said the results indicate that exercise could help amplify the benefits of therapy for adults with depression.
“With such a small group, we didn’t do formal statistical tests, but the results are promising,” Meyer said. “Overall, the pilot study showed that people were interested in and would adhere to the combined approach, and that exercise seemed to have some effects on depression and some of the mechanisms of therapy.”
One such mechanism relates to the relationship between a client and a therapist. If someone feels a connection with their therapist, Meyer said, there’s a greater chance that he’ll continue to come to therapy, and the sessions are likely to have a greater impact.
In the pilot study, participants who exercised before their cognitive behavioral therapy session reported a faster and stronger connection with their therapists. The researchers said the findings suggest that exercise may be priming or “fertilizing” the brain to engage in more emotionally challenging work that can occur during therapy.
The researchers said they hope to expand groundbreaking studies in the coming years to better understand how exercise might be incorporated into an effective treatment or intervention for people experiencing chronic depression.
