It is common knowledge that exercise is essential for good health. Now, a new study shows that senior citizens with moderate levels of physical activities have better chances of maintaining mobility in old age.

Adults who can't walk in old age become home-bound. Loss of mobility affects daily chores as well as the mental health of the person. The study, conducted by the University of Florida, found that physical activity could help seniors preserve their mobility.

"The very purpose of the study is to provide definitive evidence that physical activity can truly improve the independence of older adults," said principal investigator Marco Pahor, director of the UF's Institute on Aging.

According to Jack Guralnik, a professor of epidemiology and public health at the University of Maryland School of Medicine, exercise also cuts the risk of permanent loss of mobility.

In the present study, loss of mobility was defined as the inability to walk 400 meters, which is roughly a quarter of a mile. It might not sound much, but elders who can't walk for quarter mile can lose their independence.

"Four hundred meters is once around the track or from the parking lot to the store or two or three blocks around your neighborhood," Guralnik said in a news release. "It's an important distance in maintaining an independent life."

Data for the study came from 1,635 sedentary men and women aged between 70-89 years. Researchers divided participants into two groups. One set of 818 participants walked 150 minutes per week and did strength and flexibility exercises. The other group attended educational classes about health and did basic stretching exercise. All the participants were followed for about 2.6 years.

Study results showed that people in the exercise group were 18 percent less likely to fail the 400-meter walk test and had a 28 percent lower risk of mobility loss, USA Today reported.

There was one unanticipated finding though. Researchers found that reports of hospitalizations among those in the exercise group were higher than the rest. But, these reports weren't statistically significant. According to researchers, the exercise group was regularly monitored, which could have increased the chances of health diagnosis faster. Researchers plan on studying this occurrence more closely.

National Institutes of Health and National Institute on Aging Cooperative Agreement funded the study and it will be published in the Journal of the American Medical Association. The study findings were presented May 27 at the annual meeting of the American College of Sports Medicine in Orlando.

Centers for Disease Control and Prevention (CDC) recommends that people get two hours and 30 minutes (150 minutes) moderate intensity physical activity every week. If you have a heart condition, then you need to consult a physician before starting any new exercise program.