WASHINGTON - PEOPLE over 60 who exercise and are fit live longer than their sedentary peers, regardless of weight and body mass, researchers have found.

In a study published in the Journal of the American Medical Association on Tuesday, researchers showed that obesity and sedentary habits increased the risk of death in middle-aged adults.

The study, carried out by University of South Carolina researchers, tested the premise for the first time among older adults.

'We observed that fit individuals who were obese had a lower risk of all-cause mortality than did unfit normal-weight or lean individuals,' said Dr Xuemei Sui, the study's lead author. 'Our data therefore suggest that fitness levels in older individuals influence the association of obesity to mortality.' The 1979-2001 research focused on the relation between cardiovascular fitness and adiposity and death rates among 2,063 adults aged 60 years and older.

The 450 people who died during the study were older, less fit and at greater risk of heart disease than those who survived.

Physical fitness was assessed by a treadmill exercise and obesity was measured by body mass index, waist circumference and the percentage of body fat.

The article suggests that out-of-shape older adults start exercising.

'We don't say in this paper that obesity and fat distribution should be ignored,' said Mr Steven Blair, a member of the study team.

'I just want to get people looking beyond simple weight. There are other very important things, and one of them is fitness.'

He added: 'The recommended guidelines of 30 minutes a day, five days a week, of light to moderate exercise is a very good place to begin.

'It will make you fit, and it will dramatically improve your health and function. And it does that whether you lose a lot of weight or not.'

By 2030, 22 per cent of the US population, or 70 million people, will be older than 65, according to the study.

AGENCE FRANCE-PRESSE, BLOOMBERG