Individuals who become more physically active in middle age or later in life significantly lower their risk of an early death from cardiovascular disease, cancer and other causes by up to almost 50 percent — even if they were inactive when they were younger or had previous serious health problems, according to a new British study published in The BMJ.
This is good news for people who have been life-long couch potatoes. The study’s findings suggest that’s it’s never too late to start exercising.
Of course, plenty of previous studies have linked physical activity to a longer life. Many of those studies have, however, relied on a single assessment of the level of people’s physical activity. As a result, they weren’t able to take into account how their participants’ exercise habits changed over time — a factor that may have skewed their results. A few studies have tracked people’s activity levels over longer periods, but they tended to be small.
The current study attempts to address those limitations. Led by researchers at the University of Cambridge, the study included 14,599 men and women, aged 40 to 79, who had been recruited into a larger, ongoing study between 1993 and 1997. The participants filled out four detailed questionnaires, spaced roughly two years apart, that assessed their levels of physical activity both at work and at home. Other health-related risk behaviors, such as the participants’ dietary choices, were also assessed.
The study followed the participants through March 2013. By that date, 3,148 of them had died, including 950 from cardiovascular disease and 1,091 from cancer.
After controlling the data for risk factors such as medical history, blood pressure, weight and diet, the study found that people in the study with high levels of physical activity — who met the minimum recommended level of 150 minutes of moderate- to vigorous-intensity exercise each week — were 46 percent less likely to have died during the study period than people who were inactive.
People who met the minimum recommended level of exercise at the start of the study and who then increased their level of exercise as they got older lowered their risk the most. But the researchers also found that people who were inactive at the start of the study but who gradually, over five years, increased their physical activity to meet the minimum weekly recommended level were also less likely to have died — by 24 percent. More specifically, their risk of dying from cardiovascular disease was 29 percent lower, and their risk of dying from cancer was 11 percent lower, than the people who remained inactive.
Those findings held even among people with a history of cardiovascular disease and cancer.
Limitations and implications
This study was observational, so it can’t prove that regular exercise lowers the risk of early death. Other factors, not controlled for in the study, may also explain the results.
But, as the researchers note in their paper, we must rely on observational studies for this topic as it would be virtually impossible to study the effects of exercise on the risk of early death in a long-term randomized controlled trial (considered the gold standard for clinical research). In a clinical trial, you’d have to instruct some of the participants (the control group) to not exercise, and that would raise all sorts of practical — and ethical — problems.
So we are left with observational studies. The findings from this latest one are particularly noteworthy because the study tracked people’s activity levels over a period of years.
The findings should help inspire people of all ages to pick up the pace when it comes to physical activity.
“These results are encouraging, not least for middle aged and older adults with existing cardiovascular disease and cancer, who can still gain substantial longevity benefits by becoming more active, lending further support to the broad public health benefits of physical activity,” the authors of the study write in their paper.
“In addition to shifting the population towards meeting the minimum physical activity recommendations, public health efforts should also focus on the maintenance of physical activity levels, specifically preventing declines over mid to late life,” they conclude.
FMI: The study can be read in full on The BMJ’s website. You’ll find information on how to incorporate more physical activity into your daily life on the National Heart, Lung and Blood Institute’s website.