Sitting around too much increases the risk of heart failure in men even when they exercise regularly, a study has found.

Physical activity alone is not enough to stave off heart failure, said experts. A reduced level of sedentary behaviour, such as sitting for long periods in front of a TV or computer, was needed too.

“Be more active and sit less – that’s the message here,” said lead scientist Deborah Young, from healthcare providers Kaiser Permanente in Pasadena, California.

The researchers studied a diverse group of 84,170 men aged 45 to 69, none of whom started out with heart failure.

Participants’ exercise levels were calculated in METs, or “metabolic equivalent of task”, a measure of the body’s energy use. The number of hours they spent sitting each day was also counted.

Over a period of eight years, men who took little exercise were 52 per cent more likely to develop heart failure than those with high activity levels, even after adjusting for differences in sedentary time.

Outside work, men who spent five or more hours a day sitting were 34 per cent more at risk of heart failure than those who sat for no more than two hours.

This was true regardless of how much the men exercised when they were not sitting down.

The findings appear in the latest edition of the American Heart Association journal Circulation: Heart Failure.

Heart failure occurs when the heart is too weak to pump blood around the body efficiently. Symptoms include extreme fatigue, breathlessness, and swollen ankles.

Heart disease, high blood pressure and damaged heart valves all increase the risk of heart failure.

A second paper in the same journal linked lower rates of peripheral artery disease (PAD) to Mediterranean diets rich in fruits, vegetables, fish and healthier fats such as olive oil.