19 Mar 2023

Dr Paddy Dempsey: 11 minutes of exercise

From Sunday Morning, 8:42 am on 19 March 2023

How much exercise do we really need to stay healthy? 

Only 11 minutes of brisk walking a day could help prevent premature death, according to new research.

a pair of legs crossing a road

Photo: Tyler Nix

Kiwi medical scientist Dr Paddy Dempsey works for Melbourne's Baker Heart & Diabetes Institute and was involved in the Cambridge University study.

He Jim Mora it was effectively a large systematic review and meta-analysis of existing research.

“It summarises the results of all the literature out there - around 2,200 peer-reviewed articles and around 300 million study cohorts."

Using this data, Dr Dempsey and his fellow researchers could explore how different amounts of exercise correlate with the risk of early death from cardiovascular disease or cancer.

“The analysis focused around [how much exercise] is generally recommended in public health recommendations, which is 150 minutes a week, or the equivalent of 22 minutes a day. So that was shown to have substantial health benefits for these outcomes.

“But what was also interesting was that even half that amount, so 75 minutes a week or the equivalent of 11 minutes a day, was actually still associated with quite substantial lowering and the risk of early death around about 23 percent lowering risk.”

The study focused on moderate-intensity physical activity, which is effectively the rate of exertion at which you can talk but not sing.

“A brisk walk while having a conversation with someone you're walking with that will be classed as moderate intensity.

“Whereas when we go up to vigorous, it becomes harder to hold a conversation, you're more out of breath.”

For those doing very little exercise at the moment this is a very encouraging finding, he says.

“It may seem daunting to meet those public health guidelines initially. But if they even do half of them and they work their way up from there, they'll find some benefits. So, every little bit helps.”

This new finding is consistent with World Health Organisation guidelines regarding physical activity which are that every move counts.

Dr Dempsey's message for people with sedentary jobs is to build some activity into every day.

“A person who's stuck in an office all day, sometimes they might not be able to change that. There are things you can do within the office workspace that can be helpful.

“People nowadays are using things like standing desks or trying to have walking meetings.

“So, basically [finding] ways to try and include more movement throughout their day.”