MONDAY, Nov. 6, 2017 (HealthDay News) -- Ladies, slip on your sneakers and walk briskly every day, and you might prolong your life.
In a new study, women who logged an average of nearly 70 minutes daily had up to a 70 percent lower risk of death compared to the least active women, who moved just eight minutes a day. The study also found that the benefits were significant mainly for women who participated in moderate to vigorous exercise.
"Overall, this study's results are consistent with other evidence that repeatedly demonstrates the importance of regular activity, like brisk walking," said American Heart Association spokesperson Dr. JoAnn Manson.
"This study provides further evidence that you can literally walk away from the grim reaper. Exercise really is as close as we come to a magic bullet for good health. Exercise reduces the risk of type 2 diabetes, obesity, heart disease, cancer, depression and cognitive [mental] decline," Manson said.
The researchers said that what makes their findings stand out is the fact that exercise levels were measured objectively.
The study's lead author, Dr. I-Min Lee from Brigham and Women's Hospital in Boston, said, "The idea that physical activity is good for your health is nothing new." What is new about the current study is that the researchers didn't rely on people to tell them how much they exercised. Instead, the women in the study wore a fitness device to actually measure how much they were moving.
"Most studies see a 20 to 30 percent reduction in the risk of death. The effect of physical activity in our study was very striking, with a risk reduction on the order of 60 to 70 percent," Lee said. To put that finding into perspective, she said, the mortality risk reduction for quitting smoking is around 50 percent.
The study included data from nearly 17,000 women. Their average age was 72, and most were white. All wore an ActiGraph accelerometer that was very sensitive to picking up movement, Lee said.
The women were asked to wear the device every day for a week while they were awake. The device had no display that the women could see. The researchers asked the women to do a usual amount of activity while they were wearing the devices.
The average time of moderate to vigorous activity for all women was 28 minutes a day. The women also did 351 minutes, on average, of light physical activity daily. Light physical activity would include housework or slow walking (such as window shopping). The women were sedentary for 503 minutes a day, the study revealed.
During an average follow-up time of just over two years, 207 women died.
The more women participated in moderate-to-vigorous exercise, the less likely they were to die during the study, the findings showed.
Surprisingly, the researchers didn't see a benefit to greater levels of light activity. They also didn't see a bump in risk for those with more sedentary behavior.
Lee said it's important to remember that "health is more than death rates," and she thinks if the study had looked at other health outcomes, there likely would have been a benefit to light activity. She added that even older women -- such as those approaching 80 -- might also see a bigger benefit from increasing levels of light activity and decreasing levels of sedentary time.
Due to the design of the study, it cannot prove a cause-and-effect relationship, but Lee said that "it's more likely than not that this relationship is probably causal."
Dr. Howard Selinger, chair of family medicine at the Frank H. Netter School of Medicine at Quinnipiac University in Connecticut, said he was surprised by the magnitude of the reduction in death risk, but not that exercise was beneficial.
"I tell my patients to get 30 minutes of exercise a day, five days a week," Selinger said, which falls in line with the U.S. national guidelines that advise 150 minutes of moderate activity a week, or 75 minutes of vigorous activity.
"Get as much exercise as you can get because it may have a life-sustaining benefit," Selinger recommended.
The study was published Nov. 6 in Circulation.
Learn more about the benefits of exercise from the U.S. Centers for Disease Control and Prevention.