Thanks to scientists collecting and analyzing vast amounts of data, we know a lot about exercise and how it's good for your health.
We know stuff like the optimal time of day to exercise, how often you should exercise, and what kind of intensity you should aim for.
Many of these are just recommendations, of course, but they're based on aggregated data recorded from thousands of participants, showing what appears to work best for most people – and from lots of different perspectives too.
For instance, they can tell us interesting and useful factoids, such as how much exercise is needed to offset sitting down all day, or how best to keep weight off, and how even just one, single workout can deliver health benefits.
All of these studies have insights we can learn from and try to apply to our own lives. But if you're like most people, one of the biggest problems about exercise is simply finding time to actually do it during the week.
On that front, scientists also have some news. And it's good news.
In a new international study, researchers analyzed public health data for over 350,000 people in the US collected through the National Health Interview Survey (NHIS) between 1997 and 2013.
Combing through the data, the team – led by first author Mauricio dos Santos, an exercise physiology researcher from the Federal University of São Paulo in Brazil – had a single question they wanted to explore.
Put simply, provided you're doing enough exercise to meet the recommended levels of physical activity each week, does it matter if you do the exercise in just one or two sessions (aka 'weekend warriors'), or is it better to spread the physical activity out in three or more regular sessions during the week?
Currently, the World Health Organization (WHO) 2020 guidelines on physical activity and sedentary behavior stipulate that adults should do 150–300 minutes of moderate intensity physical activity each week, or 75–150 minutes of vigorous intensity exercise each week (or some equivalent combination thereof).
While studies have previously looked at the health benefits of being a 'weekend warrior', it's remained unclear how doing only one or two sessions of exercise a week compares to doing more frequent sessions of physical activity, specifically in terms of reducing risk of mortality.
Thanks to dos Santos and co., we now have a clearer answer.
After comparing people in the cohort who undertook the recommended level of moderate to vigorous physical activity (MVPA) each week, the researchers found very little difference between weekend warriors and the participants who exercised more regularly, in terms of reduced mortality risk from all causes, or specifically from cancer or cardiovascular disease.
"We found that weekend warrior and regularly active participants had similar all-cause and cause-specific mortality, suggesting that when performing the same amount of physical activity, spreading it over more days or concentrating it into fewer days may not influence mortality outcomes," the study authors write in their paper.
The most important takeaway – rather than worrying about how often or when you should be exercising – is making sure you do try to hit the recommended levels of activity each week, because that's when the beneficial of effects of exercise can most clearly be seen.
Over the course of 10.4 years (the median length of time which participants were involved in the survey), almost 22,000 people involved in the NHIS passed away. Among all participants, however, the statistical likelihood of dying from various causes was generally significantly lower if they did the recommended levels of physical activity.
"The findings of this large prospective cohort study suggest that individuals who engage in active patterns of physical activity, whether weekend warrior or regularly active, experience lower all-cause and cause-specific mortality rates than inactive individuals," the team explains.
"Compared with physically inactive participants, hazard ratios for all-cause mortality were 0.92 for weekend warrior and 0.85 for regularly active participants; findings for cause-specific mortality were similar."
The researchers note some limitations of their analysis, including that the primary survey data came from self-reported questionnaires, which are prone to including a certain level of error compared to more objective measurements.
On the plus side, the findings here involve a huge cohort observed over a long period, which can give us a considerable amount of confidence in the statistics reported.
Ultimately, the results confirm a lot of what we already know: Exercise is good for you, and for many of us, doing enough of it can help us to live longer.
What's more, that's true even if you're time-poor, as long as you can make time on the weekends to fit in a good workout or two.
"For people with fewer opportunities for daily or regular physical activity during their work week, these findings are important," the researchers explain.
The findings are reported in JAMA Internal Medicine.