Only half of the UK population gets enough sleep and up to 12 million Britons do not do any exercise – while still believing they are fit for their age.

A report on the nation’s health by YouGov, published jointly by private health care operator BUPA and health club chain Fitness First, assessed the lifestyles of 8,000 Britons by using a range of aspects that impact health including diet, alcohol consumption, smoking, stress and fitness.

According the survey, more than half of those assessed are doing less than two hours exercise a week – below the government recommended level for an adult which is a minimum of 30 minutes of at least moderate exercise five times a week.

Despite the low levels of physical activity, two thirds of respondents said they had good fitness levels and 82 per cent claimed they drank alcohol moderately.

Dr Annabel Bentley, BUPA's assistant medical director, said: “
This research is eye-opening to current attitudes towards general wellbeing and it seems British people are in denial about how inactive they are.

“One in five people claim to do no exercise at all, but believe they are fit and healthy. Being physically active has proven health benefits as people who exercise reduce the risk of heart disease, strokes and type 2 diabetes by up to 50 pre cent and the risk of dying prematurely by 20-30 per cent."