Research involving almost 400 middle-aged men and women found that those who had a nap at noon later had lower blood pressure than those who stayed awake through the day.

The findings, presented at the European Society of Cardiology annual conference in London, showed pressure was lower both when awake and later, during their night time sleep.

The small difference – of around 5 per cent – was enough to have a significant impact on rates of heart attack, researchers said.

Far smaller reductions have been found to reduce the chance of cardiovascular events by 10 per cent, the cardiologists said.