A new study says that just 20 minutes of activity a week can improve mental health.

The study, published in the British Journal of Sports Medicine, indicated that any type of physical activity was linked with a lower risk of mental distress.

Activities included housework, gardening, walking and playing sports.

In the study, the authors wrote: "Different types of activities, including domestic (housework and gardening), walking and sports, were all independently associated with lower odds of psychological distress, although the strongest effects were observed for sports."

Activities like housework and walking reduced the risk for mental distress by between 13 and 20 per cent. Playing sports led to the greatest improvement in mental health, lowering the risk of distress by 33 per cent.

The authors concluded: "Mental health benefits were observed at a minimal level of at least 20 min/week of any physical activity, although a dose-response pattern was demonstrated with greater risk reduction for activity at a higher volume and/or intensity."

The research was gleaned from data from the Scottish Health Survey. Almost 20,000 people who participated provided information about their mental health and their weekly level of physical activity.

Researchers noted that physical activity not only leads to better mental health, but it also reduces the known risk factors for a variety of illnesses, which range from heart disease to certain types of cancer. Studies have also shown that physical activity can decrease the risk for dementia.


Abstract:

Dose-response relationship between physical activity and mental health: the Scottish Health Survey

M Hamer, E Stamatakis, A Steptoe

Objectives: Regular physical activity is thought to be associated with better mental health, although there is a lack of consensus regarding the optimal amount and type of activity to achieve these benefits. The association between mental health and physical activity behaviours was examined among a representative sample of men and women from the Scottish Health Surveys.

Methods: Self-reported physical activity was measured and the General Health Questionnaire (GHQ-12) was administered in order to obtain information on current mental health. Participants were 19 842 men and women. Risk estimates per category of physical activity sessions per week were calculated using logistic regression models.

Results: Psychological distress (based on a score of 4 or more on the GHQ-12) was evident in 3200 participants. Any form of daily physical activity was associated with a lower risk of psychological distress after adjustment for age, gender, social economic group, marital status, body mass index, long-standing illness, smoking and survey year (OR 0.59, 95% CI 0.52 to 0.66, p,0.001). A doseresponse relationship was apparent, with moderate reductions in psychological distress with less frequent activity (OR 0.67, 95% CI 0.61 to 0.75). Different types of activities including domestic (housework and gardening), walking and sports were all independently associated with lower odds of psychological distress, although the strongest effects were observed for sports (OR 0.67, 95% CI 0.54 to 0.82).

Conclusion: Mental health benefits were observed at a minimal level of at least 20 min/week of any physical activity, although a dose-response pattern was demonstrated with greater risk reduction for activity at a higher volume and/or intensity.