Risk of death among elderly men lowered by increasing physical activity

A new study published in the British Journal of Sports Medicine links half an hour of physical activity, 6 days a week, with a 40% lower risk of death among elderly men.

Men who took regular moderate to vigorous exercise lived for 5 years longer on average than sedentary men.

The researchers behind the study, from the Norwegian School of Sports Sciences in Oslo, Norway, examined data from participants enrolled in the Oslo Study. 

As part of the Oslo Study, about 15,000 Norwegian men born between 1923 and 1932 submitted themselves for a health check in 1972-73.

At the health check, data was collected from the participants on height, weight, cholesterol, blood pressure, smoking status and physical activity levels. 

The participants were categorized according to level of physical activity as follows:

• Sedentary (watching TV/reading)
• Light (walking or cycling, including to and from work for at least 4 hours a week)
• Moderate (formal exercise, sporting activities, heavy gardening for at least 4 hours a week)
• Vigorous (hard training or competitive sports several times a week).

In 2000, 5,738 of the surviving participants repeated the health check and were monitored for 12 years to investigate any associations between the physical activity levels of the participants and risk of death. During this monitoring period, 2,154 of the remaining participants died.

Just 1 hour of exercise a week linked with lowered risk of death

Analyzing the data, the study authors found that less than 1 hour per week of light physical activity was not associated with risk of death from any cause. However, more than 1 hour of physical activity per week was linked with a 32-56% decrease in risk.

For vigorous physical activity, less than an hour per week was linked with a reduced risk of 23-37% for death from any cause. 

Men who took regular moderate to vigorous exercise lived for 5 years longer on average than sedentary men.

Overall, 30 minutes of light or vigorous physical activity, 6 days a week, was linked to a 40% reduction in risk of death from any cause.

The authors also report that when they factored in how risk of death from heart disease and stroke rises with age, this only made a slight difference to the results.

However, the authors point out that in this kind of observational study it is difficult to be conclusive about cause and effect. 

For instance, it may be only the healthiest participants from the first wave of the study who took part in the second wave, so this may have resulted in the overall risk being lowered.

Despite this, the researchers say that the differences in outcome between physically active and sedentary groups were so striking - even at the age of 73 - that they argue more effort should go into encouraging elderly men to increase physical activity. 

A wide range of health problems could be prevented by this simple lifestyle change, conclude the authors.

In 2014, a team from the Karolinska Institutet in Sweden reported that men who walked or cycled for 20 minutes or more each day were 30% less likely to die from any cause and 39% less likely to die from prostate cancer, compared with men who did less than this amount of exercise each day.

References:

1.  Increases in physical activity is as important as smoking cessation for reduction in total mortality in elderly men: 12 years of follow-up of the Oslo II study, British Journal of Sports Medicine, doi: 10.1136/bjsports-2014-094522, published online 14 May 2015.