Short bursts of vigorous activity can cut risk of early death

Whether it is playing with the dog or attacking the housework, clocking up just a few minutes of vigorous activity in daily life could dramatically reduce the chance of early death, research suggests.

The study found middle-aged adults who do not undertake leisure exercise such as going to the gym but who manage to rack up three very short bouts of vigorous activity a day have about a 39 per cent lower risk of death than those who do no vigorous activity.

A professor of sport and exercise medicine at University College London and a co-author of the study, Mark Hamer, said the findings highlighted the importance of incidental exercise.

“This could be a thing like playing with children. It could be [that] you see your bus just about to leave so you have to walk extremely quickly to get the bus. It may be that you live in a block of flats and you have to carry that shopping up a flight of stairs,” he said. “It’s those sorts of little bursts that would happen in everyday life.”

Writing in the journal Nature Medicine, Hamer and colleagues report how they analysed data from the UK BioBank – a research endeavour that has collated genetic, lifestyle and health information from more than 500,000 people since it began in 2006.

The team focused on more than 25,000 participants, with a mean age of 61.8 years, who reported that they did not undertake exercise in their leisure time, bar up to one recreational walk a week. As part of the BioBank study these participants also wore an activity tracker on their wrist for a seven-day period.

The team found almost 89 per cent of the participants undertook short bouts of vigorous activity, the vast majority of which lasted just one or two minutes.

The researchers tracked the health outcomes of participants for an average of 6.9 years, finding that 852 died, including 511 cancer deaths and 266 deaths from cardiovascular disease.

After taking into account factors such as smoking status, age, sex, and medications, the team found those who undertook just three one-minute bouts of vigorous activity each day had a 39 per cent lower risk of death from any cause in the follow-up period than those who did no such activity, while 11 one-minute bouts a day was linked to a 48 per cent lower risk of death.

The impact was even more pronounced for cancer and cardiovascular disease.

Participants who managed three one-minute bouts of vigorous activity each day had a 49 per cent lower risk of death from cardiovascular disease and a 30 per cent lower risk of death from cancer, compared with those who did no such activity, while 11 one-minute bouts a day was linked to a 65 per cent lower risk of death from cardiovascular disease and a 49 per cent lower risk of death from cancer.

The team noted the results held even when they excluded participants who had health problems at the start of the study.

“It’s a large effective study,” said Hamon, adding that the results were similar when the team looked at bouts of any vigorous activity in 62,000 additional BioBank participants who did undertake exercise in their leisure time.

Adults are currently recommended to undertake 150 minutes of moderate to brisk exercise – or 75 minutes of intense activity – a week. However, updated guidelines released by the UK’s chief medical officers in 2019 suggested even very short bursts of exertion could count towards these goals.

“The message anything counts is a really good one,” said Hamer. “I think most people can probably try to be more active in just everyday life and it doesn’t mean you have to take out a gym membership.”

Also, a new study of twins indicates consistent exercise can change not just waistlines but the very molecules in the human body that influence how genes behave.

The Washington State University study, published in the journal Scientific Reports, found that the more physically active siblings in identical twin pairs had lower signs of metabolic disease, measured by waist size and body mass index. This also correlated with differences in their epigenomes, the molecular processes that are around Deoxy ribonucleic Acid (DNA) and independent of DNA sequence, but influence gene expression.
The more active twins had epigenetic marks linked to lowered metabolic syndrome, a condition that can lead to heart disease, stroke and type 2 diabetes.

Since the identical twins have the same genetics, the study suggests that markers of metabolic disease are strongly influenced by how a person interacts with their environment as opposed to just their inherited genetics.

“The findings provide a molecular mechanism for the link between physical activity and metabolic disease,” said Michael Skinner, WSU biologist and the study’s corresponding author. “Physical exercise is known to reduce the susceptibility to obesity, but now it looks like exercise through epigenetics is affecting a lot of cell types, many of them involved in metabolic disease.”

The researchers collected cheek swabs of 70 pairs of identical twins who also participated in an exercise study through the Washington State Twin Registry. A team led by WSU Professor and Registry Director Glenn Duncan collected data on the twins at several different points in time from 2012 to 2019. They used fitness trackers to measure physical activity and measured the participants’ waistlines and body mass indexes. The twins also answered survey questions about their lifestyle and neighborhoods.

Many of the twin pairs were found to be discordant, meaning they differed from each other, on measures of physical activity, neighborhood walkability and body mass index.

An analysis by Skinner’s lab of the cells in the discordant twins’ cheek swabs revealed epigenetic differences too. The twin in the discordant pair with a high level of physical activity, defined as more than 150 minutes a week of exercise, had epigenetic alterations in areas called DNA methylation regions that correlated with reduced body mass index and waist circumference. Those regions are also associated with over fifty genes that have already been identified as specific to vigorous physical activity and metabolic risk factors.

Scientists have previously noted that the majority of identical twins develop different diseases as they get older even though they have the same genes. Epigenetics may help explain the reason why, said Skinner.

“If genetics and DNA sequence were the only driver for biology, then essentially twins should have the same diseases. But they don’t,” said Skinner. “So that means there has to be an environmental impact on the twins that is driving the development of disease.”