By Kathryn Doyle
NEW YORK (Reuters Health) - People who run in their spare time, even if it’s not very fast or very far, tend to have a lower risk of dying from heart disease or from any cause than non-runners, according to a new study.
The study was large but was observational, meaning the researchers asked participants about their running habits rather than randomly assigning them to running and non-running groups. So they cannot conclude that running, and not other differences between participants, was responsible for the lower risks.
It’s difficult to use more rigorous randomized controlled trials to look at outcomes like death, because that takes so long to track, said lead author Duck-chul Lee, from the College of Human Sciences at Iowa State University in Ames.
He said the current study is the largest on this topic, but it would still be useful to conduct randomized trials to look at the effects of running on blood pressure and cholesterol, for instance.
The researchers studied more than 55,000 generally healthy adults between ages 18 and 100. Participants answered questions about their physical activity habits over the past three months, including running speed, duration and frequency. Some were not runners at all; the rest were divided into five groups based on how much they ran each week.
The researchers then tracked the participants using their medical records for an average of 15 years.
About 3,400 people died during that time, including roughly 1,200 from cardiovascular causes, including heart disease and stroke.
At the start, runners were more often male, younger and leaner. Compared to non-runners, people who ran at all were 30 percent less likely to die during the study period and 45 percent less likely to die from cardiovascular disease.
Runners had a reduced risk of death even if they ran for less than 51 minutes or less than six miles per week, and even if they ran at a pace slower than six miles per hour, according to results published in the Journal of the American College of Cardiology.
“I think the findings are very encouraging since the study suggests that you don’t necessarily have to aim for a marathon in order to obtain the health benefits of physical activity,” said Dr. Kasper Andersen of Uppsala University Hospital in Sweden.
Andersen was not involved in the new study.
“I guess you can interpret this as every time you go running you are putting savings in your own health bank - an investment that gives you a longer life,” he told Reuters Health by email.
Running was linked to better health regardless of sex, age, smoking status or weight, the researchers found. Runners had life expectancies three years longer than non-runners, on average.
“The (World Health Organization) guidelines recommend at least 75 minutes per week of vigorous aerobic activity such as running,” Lee told Reuters Health in an email. “However, we found mortality benefits in runners who ran even as little as 30 to 60 minutes per week.”
There haven’t been as many studies on the benefits of vigorous activity as there have been for moderate activity, he said.
“As far as recommending that people go for short jogs everyday, I do think this is something we could recommend, although with a couple caveats,” said Andrea Chomistek, from the School of Public Health at Indiana University Bloomington.
“For individuals who are currently inactive, they should probably start with walking and ease into running,” she told Reuters Health in an email. “For inactive individuals who are older or have medical issues, they may want to check in with their physician before starting a running program, although walking is just fine.”
Finding a running buddy can be good motivation, Chomistek said.
“If you know that someone is counting on you to show up, you'll be more likely to go,” she said. “And longer runs are definitely more fun if you have company.”
SOURCE: http://bit.ly/1nND4lC Journal of the American College of Cardiology, online July 28, 2014.