11 Oct 2018

Could physical activity prevent mental ill-health?

From Nine To Noon, 9:33 am on 11 October 2018

A walk with friends a couple of times a week could help prevent mental ill health, according to new research.

Walking

Walking Photo: 123RF

The study by Sport New Zealand shows light physical activity done throughout the week has a positive impact on mental wellbeing.

It found people who do two a half hours of light physical activity each week have 51 percent higher odds of good mental health than those who don't.

Participation in light exercise at least 4.5 hours a week increases the odds to 65 percent.

It's the first study of its kind to look at the mental health impact of light exercise, like walking or gardening, in New Zealand.

Examining the link between recreational physical activity and well being, the 'Active' survey was completed by 25,000 New Zealand adults.

Senior evaluations advisor of Sport New Zealand and senior researcher at the University of Sydney, Dr Justin Richards, told Nine to Noon to get the best benefit, it's important physical activity is spread across the week.

"You have to be active on at least two days a week for you to realise those mental health benefits... you get additional benefits from three days, further benefits of four days, further benefits from five days and it seems to plateau at six and seven days."

He said essentially, light activity is when you're active and you have an increase in your breathing rate but it's not a noticeable increase. 

"Physical activity recommendations historically have been based on cardio-respiratory and metabolic outcomes... so cardiovascular disease, heart disease and diabetes. We've had these recommendations of two and a half hours per week of moderate to vigorous activity, because that's what's been needed to reach these health outcomes. We've not really considered what light intensity does."

It's important to think about how we encourage people to be active, he said.

"If you can actually sell someone, well actually getting out there for a walk to start with, with some friends, or just being active at a light intensity is going to have some benefit for you, it's a completely different message to saying, you've got to get out there and huff and puff it you want to have this benefit."

He said physical activity also has a role in managing both mild and severe mental illness, including psychosis, depression and anxiety.

"Physical activity itself can prevent anywhere between 10 to 25 percent of incidence of depression across the life span, depending on the age of the people we're talking to." 

People who experience mental illness die 10-25 years earlier than their counterparts, he said.

He acknowledged that people who are more active are more likely to have better mental wellbeing and thus are more likely to get out and be active.

"There has to be a starting point, there has to be an in-point."