A US study has shown that physical fitness is a better indicator of lifespan and death risk than high blood pressure, high cholesterol or smoking.

The study by researchers from the Veterans Affairs Palo Alton Health Care System and Stanford University in California tested over 6,200 men for cardiovascular disease on a treadmill and found that the risk of death over the next six years declined as exercise capacity rose. This was true for men with cardiovascular disease and without.

In the tests, patients were hooked up to sensors and walked on a treadmill at a gradually increasing speed and angle. They continued until they were exhausted, reached their maximum heart rate, or developed chest pain.

Boston Medical Centre cardiologist Dr Gary Balady said that the study shows that the 'less fit' can improve their survival chances by becoming more physically active. He adds that although the study only included men, 'there is no reason to believe that its conclusions cannot be applied to women.'