A new study has revealed one of the biggest health risks to adults today, and it's not drinking, smoking or even using a mobile phone.

Nope, it's… sitting.

Apparently an adult's risk of heart disease increases by 14% for every hour spent sitting during an average day.

Researchers from the Medical College of Wisconsin studied 2,031 adults, tracking their daily activity and taking regular blood samples. All of the adults spent between two and 12 hours per day sitting down, either at work or in front of the television.

The longer spent sitting down each day, the higher the levels of deposits in blood vessels that act as a telltale sign of heart disease.

Even regular gym or aerobic sessions did nothing to counteract the risk, as any increase in fitness was cancelled out by the many hours lacking in physical activity.

So if your job requires you to sit down all day (as many do), how can you help your body to lessen the risks?

"It’s clear that exercise is important to reduce your cardiovascular risk and improve your fitness level," said the study's lead researcher  Dr Jacquelyn Kulkinski.

“The lesson here is that it’s really important to try and move as much as possible in your daily life, for example, take a walk during lunch, pace while talking on the phone, take the stairs instead of the elevator and use a pedometer to track your daily steps… And if you have a sedentary job, don’t go home at night and sit in front of the TV for hours on end.”

Excuse us while we pop out for a quick stroll…