Run, don't walk

Taking a half-hour's brisk walk five times a week has long been held as one of the keys to a longer, healthier life.

But now a group of researchers has declared that something more strenuous is required to help prevent heart attacks or a stroke.

They even claim light exercise such as walking, and moderate exercise such as golf or digging the garden, has no impact on rates of heart disease.

Only bursts of heavy exercise, such as jogging and swimming, have any real affect on reducing death rates, they say.

The research by a team from Queen's University, Belfast, and the Medical Research Council Epidemiology Unit in Cardiff, contradicts many other studies which show light exercise, providing it is regular and frequent, can reduce the risk of premature death.

Dr John Yarnell, who led the research, said the level of exercise undertaken appeared to be more important than the amount of calories burned.

His team used data from a study of 2,000 men in Caerphilly, South Wales. The men - all aged between 49 and 64 at the start of the trial and showing no evidence of heart disease - filled in detailed health questionnaires and were monitored for more than ten years.

The researchers defined light exercise as walking, bowling or sailing, moderate exercise as golf, digging or dancing, and heavy exercise as climbing stairs, swimming and jogging. After ten years, 252 men had died, more than 75 per cent of them from heart disease or stroke and the remainder from cancer, according to the research published in the journal Heart.

Men in the least active group had the highest premature death rates, with the exception of cancer, while those undertaking most strenuous activities had the lowest death rates from all causes and from heart disease.

Dr Yarnell said: 'Moderate and light levels of regular exercise had no impact on death rates from all causes or specifically from heart disease.'

The top fifth of men in the 'heavy exercise' category reduced their risk of dying from all causes by 47 per cent and of dying from a heart attack by 62 per cent - yet they only used 54 kilocalories of energy a day doing this intense activity.

The study says that corresponds to nine minutes of jogging or tennis doubles a day or seven minutes climbing stairs.

The advice does not apply to those who already suffer from heart disease.

There is evidence that, for them, intensive exercise can bring on a heart attack.

Belinda Linden, of the British Heart Foundation, which partfunded the study, said: 'While this study adds to our understanding of how levels of physical activity affect an individual's risk of heart disease in the long term, it is just one study.

'We currently recommend that people should take moderate physical activity such as brisk walking for at least 30 minutes a day five times a week.

'Current guidelines have been developed through a consensus of national and international research over time. They have been devised to be achievable by the majority of people.'

She added: 'While we recognise that vigorous activity will provide maximum cardiac protection and promote physical fitness there is evidence that the "five times 30 minutes" moderate-intensity activity still appears to provide health benefits.

'There is not enough evidence to suggest that current messages are not appropriate.'