People who try to catch up on week's worth of exercise in one or two days may succeed in reducing the risk of premature death, compared with those who don't work out at all, according to a new study.

"Weekend warriors" — adults who perform the recommended amount of 150 minutes of moderate or 75 minutes of vigorous activity in one or two sessions per week — were found to have a risk of death from all causes about 30 per cent lower than inactive adults.

Researchers in England set out to investigate the risk of death from all causes, cardiovascular disease (CVD) and cancer was associated with physical activity patterns.

"I think it's important to reassure people that if they are a weekend warrior, if they are only exercising once or twice per week, and it's of moderate or vigorous intensity, then that's good enough," study author Gary O'Donovan, of Loughborough University, England, said in an interview. 

'The present study suggests that some leisure time physical activity is better than none.' - Study authors

The researchers focused on survey data from more than 63,000 adults aged 40 and older in England and Scotland. The self-reported data was collected from 1994 to 2012 and analyzed in 2016.

Over the study period, there were 8,802 deaths from all causes, 2,780 deaths from cardiovascular disease such as heart attacks and strokes, and 2,526 from cancer, the researchers reported in Monday's issue of JAMA Internal Medicine.

Activity of moderate intensity would cause you to break into a sweat. As a rule of thumb, if you can exercise and still carry on a conversation, then you are likely in the moderate zone. If you can no longer talk, then the activity is considered vigorous.

"Purposeful" walking and running are examples.

"The present study suggests that some leisure time physical activity is better than none," the study's authors said.

The study suggested the weekend warrior pattern is just as beneficial for women as men, which hasn't been shown before, O'Donovan said.

In the study, regular exercisers lowered their risk by 35 per cent.

Any amount of activity helped cut the risk of dying of heart disease by about 40 per cent, compared to being a couch potato. O'Donovan said he was surprised that those who weren't even weekend warriors also gained benefits. 

Since more than 90 per cent of the participants were white, the findings may or may not apply to other racial groups.

'Encouraging news'

The researchers said they can't discount the possibility that participants with underlying disease are less likely to work out, although long-standing illnesses, cardiovascular disease and cancer were considered in the analysis and deaths in the first two years of follow-up were excluded.

A journal commentary published with the study called the findings "encouraging news."

"Still, the role of physical activity patterns in reducing mortality risk may need to be considered within the context of one's sedentary patterns," Hannah Arem and Loretta DiPiotro of George Washington University in Washington, D.C. said.

Benefits of a bout of exercise

To the question of whether activity can wait for the weekend, the short answer is perhaps, the commentators said.

While aerobic fitness is one of the strongest predictors of mortality risk, physical activity has also been associated with other benefits, such as to reduce blood pressure and blood sugar levels.  

"We tend to read these high-profile media stories of course about the hockey player that you know dies on the ice, but I think if you look at the scientific evidence it would suggest that that single, weekly bout of exercise is actually beneficial," said Prof. Martin Gibala, chair of the kinesiology department at McMaster University in Hamilton, Ont. He was not involved in the latest study.

Gibala supports the public health guidelines on physical activity, which recommend 150 minutes of moderate exercise a week. "But anything is better than nothing," he said. 

While the observational study suggests exercise and health risks may be related it cannot prove it.

With files from CBC's Christine Birak