Going for a stroll after supper or puttering about in the garden may not seem much like exercise, but seniors who engage in such light activities for about 3 1/2 hours a day may add years to their lives.

Those who took to the proverbial rocking chair instead of engaging in light activities throughout the day were far more likely to die within a six-year period, the researchers found.

600 Calorie Advantage

The study, sponsored by the US National Institute on Aging (NIA) and led by Todd M. Manini, involved 302 healthy adults, ages 70 to 82.

Almost one-fourth of the least active members of the group died within the six-year follow-up period, compared to only 12 percent of those who were most active. That translates into a 50 percent reduction in mortality.

Although the people who were most active did little, if any, strenuous exercising, they did expend about 600 calories a day more, on average, than those in the least active category.

"The message here," said Manini, "is that for older adults, any movement is better than no movement, and that this can come from usual daily activities."

Just Keep Moving

There were similar incidences of diabetes, arthritis, cardiovascular disease and other age-related medical conditions among both groups of participants. More than half were affected by these health issues.

The researchers do not advise older people to avoid organized fitness programs, which might be even more beneficial than light activities. However, they point out that exercise doesn't have to be rigorous to provide benefits.

A total of about 3 1/2 hours a day of movement -- including walking, climbing stairs, household tasks, and so forth -- would qualify a person for the "most active" category. In contrast, the "least active" individuals were moving about for less than two hours a day.

"Simply expending energy through any activity may influence survival in older adults," the researchers concluded.