Previous research has shown that engaging even in low-level physical activity — including leisurely tasks, such as gardening — may help protect brain health and cardiovascular health, among other benefits.
Now, a recent observational study, working with tens of thousands of people aged 40 and over has found a link between a lower risk of death from different causes and low levels of physical activity.
This was a collaborative study by researchers from the Shandong University in Jinan, China, the University of Texas Medical Branch in Galveston, and the University of Minnesota in Minneapolis, as well as from other research institutions.
The research — whose results appeared yesterday in the British Journal of Sports Medicine — indicate that people who spend even a short time each week being physically active have a lower risk of death linked to cardiovascular, cancer, and all-cause mortality.
At the same time, the study authors note that participating in more intense types of exercise, including running and cycling, do have the potential to bring more significant health benefits.
Even low-level activity cuts death risk
The researchers analyzed data collected through the National Health Interview Surveys — a series of yearly surveys that ask people from the United States to offer information about their health and lifestyle habits.
First author Min Zhao and colleagues looked at information gathered in 1997–2008 from 88,140 adults in the U.S., with ages ranging from 40 to 85. They also collated that data, which referred to health and physical activity practices, with information from national death registers, available up to the end of 2011.
For reference, the team estimated that 1 minute of vigorous exercise would equate to 2 minutes of moderate-intensity activity, such as gardening, dancing, or going for a brisk walk. In their analysis, the researchers only included physical activities that lasted for 10 or more minutes at one time.
The researchers found that, unlike people who were very physically inactive, individuals who engaged in 10–59 minutes of moderate, leisurely physical activity per week had an 18 percent lower risk of all-cause death.
People who engaged in moderate physical activity for a little longer — between 150 and 299 minutes per week — saw an even steeper drop in all-cause death risk, of 31 percent.
And those who spent 1,500 minutes or more being physically active in their leisure time each week experienced a 46 percent decrease in their overall mortality risk.
The researchers observed similar associations between increased levels of physical activity and the risk of death related to cancer.
Finally, individuals who spent 10–59 minutes per week doing leisurely physical activities saw a 12 percent lower risk of death tied to cardiovascular events, and people who were active for 120–299 minutes every week had a 37 percent lower risk of death due to cardiovascular causes.
However, the researchers note that engaging in physical activities for much longer than 1,500 minutes per week did not bring any extra benefits in this respect.
More is not better, but more vigorous is
Although the authors acknowledge that this was an observational study that cannot determine cause and effect relationships, they also note that the considerable cohort size is representative and that their current findings support existing notions about the benefits of engaging in moderate physical activity.
Nevertheless, the results also showed that people who opted for vigorous rather than lighter physical activity had a much lower mortality risk.
“Assuming causality of the associations we observed, both low and high levels of [physical activity] have beneficial effects on all-cause and cause-specific mortality risk,” the authors conclude, adding:
“Importantly, vigorous [physical activity] has added benefits for reducing mortality compared with moderate [physical activity]. Promoting [physical activity] of any intensity and amount is an important approach to reducing mortality risk in the general population.”