Scientists say being active for short periods brings life-prolonging health benefits, even to those who only exercise once a week.
People who squeeze their work-outs into just a day or two still reduce their risk of dying from cancer and cardiovascular disease, say scientists.
A range of health benefits are achieved by the so-called "weekend warriors", who may spend most of their time sat behind desks but pound the streets, go to the gym or play sport on one or two days a week, research from the University of Sydney found.
The World Health Organisation recommends at least 150 minutes of moderate-intensity activity, or at least 75 minutes of vigorous-intensity activity every week for adults.
Compared with those who do no exercise, weekend warriors reduce their risk of death from cancer by almost 20%, and death from cardiovascular disease by 41% - the same percentage as those deemed to be regularly active.
Associate Professor Emmanuel Stamatakis, the study's senior author, said: "It is very encouraging news that being physically active on just one or two occasions per week is associated with a lower risk of death, even among people who do some activity but don't quite meet recommended exercise levels.
"However, for optimal health benefits from physical activity it is always advisable to meet and exceed the physical activity recommendations."
The study, published in the Journal of the American Medical Association Internal Medicine, assessed activity of 63,000 adults over more than a decade.
Though the findings might be good news for weekend warriors, other research shows that sitting down for long periods is bad for health - even if you do regular exercise.
Public Health England says a third of men and almost half of women do not achieve the recommended activity levels and inactivity is responsible for one in six early deaths.