15 min of daily exercise could mean longer life for elderly

Even 15 minutes of moderate to vigorous physical activity every day could help those over 60 live longer, new research has claimed.
The greatest benefit seemed to be among those who went from doing nothing or only a minimal amount of physical activity to doing more, researchers said.
Much of the health benefit seemed to be for a reduced risk of dying from heart disease or stroke, while the reduction in deaths from all causes was considerably greater in older women than it was in older men.
The health benefits of 150 minutes a week of moderate to vigorous physical activity are well known, but older adults often find this target difficult, said the researchers.

The team, which included researchers from University of Lyon, University of Burgundy and Jean Monnet University in France, wanted to know if regular activity below this level was associated with greater longevity in the elderly.
They searched research databases for studies published up to February this year, which assessed risk of death according to weekly physical activity for those aged 60 and above.

Physical activity was measured in Metabolic Equivalent of Task (MET) minutes, which express the amount of energy (calories) expended per minute of physical activity.
The MET minutes an individual clocks up every week depends on the intensity of physical activity of a person.

For example, moderate intensity activity ranges between 3 and 5.9 MET minutes while vigorous intensity activity is classified as 6 or more.
The researchers looked at the associated risk of death for four categories of weekly physical activity - inactive, low (1-499), medium (500-999), and high (1000+).
Out of a total of 835 relevant studies, nine were suitable for analysis. These involved a total of 122,417 participants, who were monitored for an average of around 10 years. During this period, 18,122 died.
Pooled analysis of the data showed that clocking up less than 500 weekly MET minutes of physical activity was still associated with a 22 per cent lowered risk of death compared with those who were inactive.

The more physical activity an individual engaged in, the greater the health benefit, reaching a 28 per cent lower risk of death for those fulfilling the recommended weekly tally of MET minutes, while more than 1000 MET minutes was associated with a 35 per cent lower risk.
The data showed that a weekly tally of 250 MET minutes, which corresponds to 75 minutes of moderate to vigorous physical activity - or 15 minutes a day - was associated with health benefits, added to which the first 15 minutes of physical activity seemed to have the greatest impact, prompting the researchers to suggest that this could be "a reasonable target dose."

The study was published in the British Journal of Sports Medicine.