Intensive exercise is healthier

Exercise is always healthy, even if you get an awful lot of it. We wrote about that recently. But does it matter whether you do high intensity exercise or take things more gently? It does, according to an article published by researchers at the University of Sydney in JAMA Internal Medicine. Exercise is even healthier if about a quarter to a third of the total amount of activity you get is made up of intensive exercise.

The researchers used data that had been gathered during the Australian 45 And Up study. They followed over two hundred thousand men and women, who were aged 45-75 at the start of the study, for over seven years.

The researchers knew how many minutes per week the participants spent doing exercise, and how many of those minutes were devoted to ‘vigorous’ exercise. “Vigorous activity is defined as activity that made you breathe harder or puff and pant, like jogging, cycling, aerobics, competitive tennis, but not household chores or gardening,” the researchers wrote.

That exercise reduces the risk of fatal cardiovascular disease and fatal forms of cancer is not new, but it is still not clear what types of activity increase our survival chances the most. That’s why the researchers made a distinction between intensive and moderate-intensive physical exercise. Moderately intensive physical activity included “gentle swimming, social tennis, vigorous gardening or work around the house”.

The more of the total number of minutes devoted to intensive exercise every week, the lower the participants’ risk of dying, as the figure below shows. The risk of dying for the participants that never engaged in intensive exercise was fixed at 1 in the figure below.


In the table below the researchers split their results up even further. As you can see, vigorous activity reduced the mortality risk in the participants who exercised relatively little and in those who exercised a lot.

MVPA = total moderate to vigorous activity; VPA = vigorous activity.


“Independent of the total amount of physical activity, engaging in some vigorous activity was protective against all-cause mortality”, the researchers wrote. “This finding applied to both sexes, all age categories, people with different weight status, and people with or without cardiometabolic disease.”

“Doing some vigorous activity might be important for increasing longevity among middle aged and older adults. If vigorous activities are consistently independently associated with health benefits, such activities should be more strongly encouraged in activity guidelines to maximize the population benefits of physical activity.”

Effect of Moderate to Vigorous Physical Activity on All-Cause Mortality in Middle-aged and Older Australians.


Few studies have examined how different proportions of moderate and vigorous physical activity affect health outcomes.

To examine whether the proportion of total moderate to vigorous activity (MVPA) that is achieved through vigorous activity is associated with all-cause mortality independently of the total amount of MVPA.

We performed a prospective cohort study with activity data linked to all-cause mortality data from February 1, 2006, through June 15, 2014, in 204,542 adults aged 45 through 75 years from the 45 and Up population-based cohort study from New South Wales, Australia (mean [SD] follow-up,?6.52 [1.23] years). Associations between different contributions of vigorous activity to total MVPA and mortality were examined using Cox proportional hazards models, adjusted for total MVPA and sociodemographic and health covariates.

Different proportions of total MVPA as vigorous activity. Physical activity was measured with the Active Australia Survey.

All-cause mortality during the follow-up period.

During 1,444,927 person-years of follow-up, 7435 deaths were registered. Compared with those who reported no MVPA (crude death rate,?8.34%), the adjusted hazard ratios for all-cause mortality were 0.66 (95% CI, 0.61-0.71; crude death rate, 4.81%), 0.53 (95% CI, 0.48-0.57; crude death rate, 3.17%), and 0.46 (95% CI, 0.43-0.49; crude death rate, 2.64%) for reporting 10 through 149, 150 through 299, and 300 min/wk or more of activity, respectively. Among those who reported any MVPA, the proportion of vigorous activity revealed an inverse dose-response relationship with all-cause mortality: compared with those reporting no vigorous activity (crude death rate,?3.84%) the fully adjusted hazard ratio was 0.91 (95% CI,?0.84-0.98; crude death rate,?2.35%) in those who reported some vigorous activity (but <30% of total activity) and 0.87 (95% CI, 0.81-0.93; crude death rate, 2.08%) among those who reported 30% or more of activity as vigorous. These associations were consistent in men and women, across categories of body mass index and volume of MVPA, and in those with and without existing cardiovascular disease or diabetes mellitus.

Among people reporting any activity, there was an inverse dose-response relationship between proportion of vigorous activity and mortality. Our findings suggest that vigorous activities should be endorsed in clinical and public health activity guidelines to maximize the population benefits of physical activity.
PMID: 25844882 [PubMed – indexed for MEDLINE]