Maintaining physical activity in adulthood reduces the risk of death

Being physically active in adulthood is associated with a 30-40% lower risk of dying from any cause later in life, while even increasing activity levels from below health recommendations is associated with a 20-25% lower risk, according to a meta-analysis of available data published online in the British Journal of Sports Medicine.

These findings led the researchers to conclude that becoming more active at any point in adulthood can extend lifespan, and that it's never too late to start.

It is currently recommended that adults aim for 150-300 minutes of moderate physical activity per week, or 75-150 minutes of vigorous physical activity per week, or a combination of the two, the researchers note.

However, although these recommendations are based on the best available evidence, most only recorded physical activity levels at one point in time, which could obscure the potential impact of changes in activity throughout adulthood, they add.

In this regard, the scientists decided to find out whether different patterns of physical activity, as well as its cumulative effect in adulthood, are associated with a reduced risk of death from all causes, as well as from cardiovascular diseases and cancer.

They searched scientific databases and included 85 studies published in English up to April 2024, with sample sizes ranging from 357 to 6,572,984 participants.

Fifty-nine studies examined long-term patterns of physical activity in adulthood; 16 examined the average benefits of different levels of physical activity; 11 examined the potential impact of cumulative physical activity on the risk of death.

To overcome the difficulties associated with the different analytical methods used in the studies, the scientists conducted separate analyses for each of them.

Pooled analysis of the data showed that overall higher levels of physical activity were associated with lower risks of all outcomes considered.

People who were consistently active (32 studies) had about a 30-40% lower risk of dying from any cause, while those who increased their physical activity levels (21 studies) from below recommended levels had a 20-25% lower risk of dying from any cause.

Specifically, participants who went from physical inactivity to activity were 22% less likely to die from any cause than those who remained inactive, and those who increased their leisure-time physical activity had a 27% lower risk of death.

On the other hand, moving from an active to an inactive lifestyle was not associated with a reduced risk of death from any cause.

Overall, associations between high levels of physical activity and reduced risk of death were stronger for cardiovascular disease than for cancer.

Compared with participants who remained inactive over time, those who were consistently active (either overall or only in leisure time) were about 40% and 25% less likely to die from cardiovascular disease and cancer, respectively.

However, overall evidence for an association between physical activity patterns and cause-specific mortality remains inconclusive, particularly for cancer mortality.

The pooled evidence suggests that people who were consistently active or became active had a lower risk of dying from all causes, and particularly from cardiovascular disease, if they achieved recommended weekly levels of physical activity.

But exceeding the maximum recommended amount of moderate or vigorous physical activity per week was associated with only a small additional risk reduction.

Maintaining or increasing physical activity levels, even if they remain below recommended levels, also produced significant health benefits, indicating that any physical activity is better than no activity at all, the researchers note.

In addition, the average amount of physical activity, meeting the recommended weekly allowance, was also associated with a 30-40% lower risk of death from any cause. However, the researchers add that more studies are needed to confirm these findings.

The researchers acknowledge some limitations to their findings, including that most studies in the meta-analysis relied on subjective assessments of physical activity levels, which may not always be accurate. In addition, only a few studies examined cumulative amounts of physical activity or cancer mortality.

Still, the findings have important public health implications, the researchers insist.

"First and foremost, our results highlight the importance of physical activity throughout adulthood, showing that starting exercise at any time can provide survival benefits."

They add:

"Because ongoing activity provides greater health benefits than past activity (such as when a person is no longer active), this highlights the importance of maintaining physical activity over time.

Future interventions to increase physical activity should not only target inactive people, but also support those who are already active to help them maintain their achieved activity levels."