A short walk each day could be enough to slash your risk of dying early, according to recent media reports based on a major new meta-analysis. What does it mean for public health messaging?

It’s hardly breaking news that exercise is good for you - or that an inactive lifestyle causes health problems.

To lead a healthy life, the NHS recommends 150 minutes of moderate-intensity activity, or 75 minutes of vigorous activity, each week. Yet over 17.6 million people in England (38.5% of the population) don’t achieve this.

The Guardian. Number of inactive adults in England rises by 1.3m since Covid, 28 April 2022.

 

 

But is 150 minutes the threshold to begin reaping the health benefits of physical activity?

New research from the University of Cambridge suggests that even half the recommended amount of exercise leads to significant benefits, and could prevent one in ten premature deaths.

This led to news outlets promising that “just 11 MINUTES of brisk walking each day is enough to slash your chances of dying early” or that a brief stroll is the “the secret to living longer”.

Let’s look at the study in a bit more detail.

 

The beneficial impact of exercise

 

The systematic review and meta-analysis, carried out by the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, was designed to estimate the association between physical activity and mortality outcomes in the general adult population.

Garcia, L, Pearce, M, Abbas, A, Mok, A & Strain, T et al. Non-occupational physical activity and risk of cardiovascular disease, cancer, and mortality outcomes: a dose response meta-analysis of large prospective studies. British Journal of Sports Medicine 2023:0;1-15 [full text].

 

 

Researchers examined 196 prospective cohort studies, looking at data for the general population from 1989-2021. This covered more than 30 million participants globally, making it the largest analysis of the topic to date.

The team looked at whether the World Health Organization (WHO) and NHS-recommended 150 minutes of moderate-intensity exercise can reduce rates of premature death, particularly from chronic and cardiovascular diseases.

Results were clear and unsurprising: it does. Participants who exercised for at least 150 minutes a week had a 31% lower risk of overall mortality - 29% and 15% lower from cardiovascular disease (CVD) and cancer respectively. Exercise was also preventive; if all 30 million participants had reached recommended levels of physical activity, 1 in 6 (15.7%) premature deaths could have been prevented, while 10.9% of CVD and 5.2% of cancer cases could have been avoided.

But there was another, more surprising finding: while more than 150 minutes of physical activity had only marginal gains, exercising for even half of that time still gave substantial health benefits.

Just 75 minutes a week of moderate activity - just over 10 minutes a day - reduced the risk of CVD by 17% and cancer by 7%. If everyone managed this, 5% of CVD and 3% of cancer cases could be prevented – and overall it could prevent 10.1% of premature deaths.

It suggests that any amount of exercise, however brief, can improve health, rather than needing to hit a certain threshold to begin benefitting from it.

One limitation is that information such as intensity of physical activity was missing from some studies, making direct comparisons between 196 papers difficult. Then there are the methodological limitations of the studies that make up the analysis, such as a reliance on self-reported questionnaires.

But the breadth of studies that this draws on, looking at over 94 different cohorts around the world, means the research provides a comprehensive examination of how physical activity benefits health.

 

Inactivity: A silent killer

 

In October 2022, the government claimed that 34% of men and 42% of women were not active enough for good health.

GOV.UK. Physical activity: applying All Our Health, 10 March 2022.

 

Physical inactivity is associated with 1 in 6 deaths in the UK and is estimated to cost the economy £7.4 billion and the NHS £900 million annually.

GOV.UK. Physical activity: applying All Our Health, 10 March 2022.

 

 

It is difficult to know how directly the meta-analysis results apply to the UK – although it incorporated some UK data among the constituent studies, the overall findings weren’t broken down by country.

But inactivity trends are only increasing in the UK.

World Health Organization. Physical Activity Fact Sheet, 5 October 2022.

 

The WHO estimates that globally almost 500 billion new cases of preventable disease will occur between 2020 and 2030 if there is no improvement in levels of physical activity.

World Health Organization. Global status report on physical activity 2022, 19 October 2022.

 

In high-income countries, treating these could eventually account for 70% of healthcare expenditure.

World Health Organization. Global status report on physical activity 2022, 19 October 2022.

 

 

 

“Some is better than none”

 

But this new analysis shows that addressing inactivity is possible. The paper concludes: “Appreciable population health benefits might be gained from increasing [physical activity] levels of people who are inactive to just half the current health recommendations.”

And physical activity doesn’t have to be intense or vigorous exercise - the research is based on moderate levels: raising your heart rate but not necessarily making you out of breath.

In a press statement, lead author Dr. Leandro Garcia, a lecturer at Queen’s University Belfast, explained that moderate activity can include walking or cycling, or even active play with children. “Doing activities that you enjoy and that are easy to include in your weekly routine is an excellent way to become more active,” he said.

University of Cambridge. Daily 11 minute brisk walk enough to reduce risk of early death, 1 March 2023.

 

The 11-minute daily walk that hit the headlines really can make a difference.

 

The paper ends with support for the WHO public health message that ‘doing some [physical activity] is better than doing none’. Reducing the emphasis on existing thresholds of physical activity could be valuable to public health, it argues.

Dr. Soren Brage, Group Leader at the MRC Epidemiology Unit, said: “If you are someone who finds the idea of 150 minutes of moderate-intensity physical activity a week a bit daunting, then our findings should be good news… This is also a good starting position.”

University of Cambridge. Daily 11 minute brisk walk enough to reduce risk of early death, 1 March 2023.

 

 

At present, the UK government recommends that healthcare professionals promote the message that 150 minutes of physical activity, spread across a whole week, is needed to stay healthy. But this meta-analysis indicates that any physical activity is a step in the right direction.