A new study showed that the mortality risk in older women in the short time could be decreased significantly by performing the more physical activity and at higher intensities. The findings were reported in the American Heart Association's journal Circulation.
Previous studies, which used self-reports showed that active people have about 20% to 30% lower death rates compared to their least active counterparts.
The researchers used a wearable device called a triaxial accelerometer to examine physical activity and a clinical outcome. The device measured the activity with three planes (up and down, front to back and side to side). The capabilities increased sensitivity to detect physical activity and allow for more precise measurements.
The study's first author I-Min Lee said, "We used devices to measure better not only higher intensity physical activities but also lower intensity activities and sedentary behavior, which has become of great interest in the last few years."
The researchers analyzed data from 16,741women out of 17,700 women who wore the device for at least ten hours per day, on at least four days (average age 72). The team found 207 women died during an average follow-up of approximately two-and-a-half years.
The association between more moderate-vigorous intensity physical activity and lower death risk at the study’s end in the most active women was found (~60% to 70%) when compared with the least active women.
However, the researchers did not find the relationship between more light intensity activity or more sedentary behavior and the mortality risk at the study's end. Light intensity activity might be beneficial for other health outcomes.
Lee said, "Younger people in their 20s and 30s generally can participate in vigorous intensity activities, such as running or playing basketball. But for older people, vigorous intensity activity may be impossible, and moderate intensity activity may not even be achievable. So, we were interested in studying potential health benefits associated with light intensity activities that older people can do."
The study outcomes suggested engaging at least 150 minutes of moderate intensity or 75 minutes of vigorous-intensity aerobic physical activity (or a combination of the two) for seven days and muscle-strengthening exercises two or more days per week.
Lee said the further research would be done to investigate other health outcomes. The details of how much and what kinds of activity are healthful would be examined.