Exercise linked to improved mental health, but more may not always be better

August 9, 2018, Lancet
Credit: CC0 Public Domain

A study of 1.2 million people in the USA has found that people who exercise report having 1.5 fewer days of poor mental health a month, compared to people who do not exercise. The study found that team sports, cycling, aerobics and going to the gym are associated with the biggest reductions, according to the largest observational study of its kind published in The Lancet Psychiatry journal.

More exercise was not always better, and the study found that exercising for 45 minutes three to five times a week was associated with the biggest benefits.

The study included all types of physical activity, ranging from childcare, housework, lawn-mowing and fishing to cycling, going to the gym, running and skiing.

Exercise reduces the risk of cardiovascular disease, stroke, diabetes, and mortality from all causes, but its association with mental remains unclear.

Previous research into the effect of exercise on mental health has conflicting results. While some evidence suggests that exercise may improve mental health, the relationship could go both ways—for example inactivity could be a symptom of and contributor to , and being active could be a sign of or contribute to resilience. The authors note that their study cannot confirm cause and effect.

"Depression is the leading cause of disability worldwide, and there is an urgent need to find ways to improve mental health through population health campaigns," says Dr. Adam Chekroud, Assistant Professor of Psychiatry at Yale University, and Chief Scientist at Spring Health, USA. "Exercise is associated with a lower mental health burden across people no matter their age, race, gender, household income and education level. Excitingly, the specifics of the regime, like the type, duration, and frequency, played an important role in this association. We are now using this to try and personalise exercise recommendations, and match people with a specific exercise regime that helps improve their mental health."

In the study, the authors used data from 1.2 million adults across all 50 US states who completed the Behavioural Risk Factor Surveillance System survey in 2011, 2013, and 2015. This included demographic data, as well as information about their physical health, mental health, and health behaviours. The study did not take mental health disorders into account, other than depression.

Participants were asked to estimate how many days in the past 30 days they would rate their mental health as 'not good' based on stress, depression and emotional problems. They were also asked how often they took part in exercise in the past 30 days outside of their regular job, as well as how many times a week or month they did this exercise and for how long.

All results were adjusted for age, race, gender, marital status, income, education level, employment status, BMI, self-reported physical health and previous diagnosis of depression.

On average, participants experienced 3.4 days of poor mental health each month.

Compared to people who reported doing no exercise, people who exercised reported 1.5 fewer days of poor mental health each month—a reduction of 43.2% (2.0 days for people who exercised vs 3.4 days for people who did not exercise).

The reduction in number of poor mental health days was larger for people who had previously been diagnosed with depression, where exercise was associated with 3.75 fewer days of poor mental health compared with people who did not exercise—equivalent to a 34.5% reduction (7.1 days for people who exercised vs 10.9 days for people who did not exercise).

Overall, there were 75 types of exercise recorded and these were grouped into eight categories—aerobic and gym exercise, cycling, household, team sports, recreational activity, running and jogging, walking, and winter or water sports.

All types of exercise were associated with improved mental health, but the strongest associations for all participants were seen for team sports, cycling, aerobic and gym exercise (reduction in poor mental health days of 22.3%, 21.6%, and 20.1%, respectively).

Even completing household chores was associated with an improvement (reduction in poor mental health days of around 10%, or around half a day less each month).

The association between exercise and improved mental health (a 43.2% reduction in poor mental health) was larger than many modifiable social or demographic factors. For example, people with a college education had a 17.8% reduction in poor mental health days compared with people with no education, people with normal BMI had a 4% reduction compared with people who were obese, and people earning more than US$50,000 had a 17% reduction compared with people earning less than US$15,000.

How often and for how long people completed exercise was also an important factor. People who exercised between three and five times a week had better mental health than people who exercised less or more each week (associated with around 2.3 fewer days of poor mental health compared with people who exercised twice a month).

Exercising for 30-60 minutes was associated with the biggest reduction in poor mental health days (associated with around 2.1 fewer days of poor mental health compared with people who did not exercise). Small reductions were still seen for people who exercised more than 90 minutes a day, but exercising for more than three hours a day was associated with worse mental health than not exercising at all. The authors note that people doing extreme amounts of exercise might have obsessive characteristics which could place them at greater risk of poor mental health.

"Previously, people have believed that the more exercise you do, the better your mental health, but our study suggests that this is not the case. Doing exercise more than 23 times a month, or exercising for longer than 90 minute sessions is associated with worse mental health," continues Dr. Chekroud.

"Our finding that team sports are associated with the lowest mental health burden may indicate that social activities promote resilience and reduce depression by reducing social withdrawal and isolation, giving social sports an edge over other kinds."

The study used people's self-reported assessment of their mental health and exercise levels so could be subject to bias. It also only asked participants about their main form of exercise so could underestimate the amount of exercise they do if they do more than one type.

Writing in a linked Comment, Dr. Gary Cooney, Gartnavel Royal Hospital, UK, says: "There is gathering interest and momentum around research into exercise as a treatment for disorders. The appeal is multifaceted: patients, particularly those reluctant to pursue medication or psychological approaches, are drawn to the self efficacy of , the ability to attain a degree of agency in their own process of recovery. Mental health professionals, for their part, recognise the urgent need to address the comparatively poor physical health outcomes in the psychiatric patient population. With very high rates of physical comorbidity, and marked reductions in life expectancy, an intervention that might improve both mental and physical health is of particular clinical interest."

Explore further: Right amount of exercise can boost mental health: study

More information: The Lancet Psychiatry (2018). www.thelancet.com/journals/lan … (18)30227-X/fulltext

Related Stories

Right amount of exercise can boost mental health: study

October 26, 2012
(HealthDay)—People who exercise 2.5 to 7.5 hours a week have better mental health, but more than that is associated with poorer mental health, a new study suggests.

Stopping exercise can increase symptoms of depression

March 22, 2018
Stopping exercise can result in increased depressive symptoms, according to new mental health research from the University of Adelaide.

Should exercise be what the doctor orders for depression?

November 8, 2017
More mental health providers may want to take a closer look at including exercise in their patients' treatment plans, a new study suggests.

Exercising with others helps college students reduce stress

September 4, 2013
College students who exercised vigorously for 20 minutes at least three days a week were less likely to report poor mental health and perceived stress, according to a study in the American Journal of Health Promotion. However, ...

One hour of exercise a week can prevent depression

October 3, 2017
A landmark study led by the Black Dog Institute has revealed that regular exercise of any intensity can prevent future depression - and just one hour can help.

Recommended for you

FDA approves brain stimulation device for OCD

August 17, 2018
(HealthDay)—A brain stimulation device to treat obsessive-compulsive disorder (OCD) has received approval for marketing Friday by the U.S. Food and Drug Administration.

Research eyes role of stress in mental illnesses

August 17, 2018
We all face stress in our lives. Even researchers seeking to understand why some people shrug it off while others face battles against disorders like depression or PTSD.

16 going on 66: Will you be the same person 50 years from now?

August 17, 2018
How much do you change between high school and retirement? The answer depends on whether you're comparing yourself to others or to your younger self.

Men and women show surprising differences in seeing motion

August 16, 2018
Researchers reporting in the journal Current Biology on August 16 have found an unexpected difference between men and women. On average, their studies show, men pick up on visual motion significantly faster than women do.

It's okay when you're not okay: Study re-evaluates resilience in adults

August 16, 2018
Adversity is part of life: Loved ones die. Soldiers deploy to war. Patients receive terminal diagnoses.

Expecting to learn: Language acquisition in toddlers improved by predictable situations

August 16, 2018
The first few years of a child's life are crucial for learning language, and though scientists know the "when," the "how" is still up for debate. The sheer number of words a child hears is important; that number predicts ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.