More than half of Australians haven’t worked up a sweat in three months.

This is despite research from Medibank – showing exercise can reduce depression, anxiety and stress.

David Dunstan, head of physical activity at the Baker Heart and Diabetes Institute told 3AW Breakfast though the numbers are hard to believe, it’s true.

“Sadly it hasn’t changed over the last two decades,” David said.

“We have a highly inactive population sadly.”

Click PLAY above to find out how much exercise we should be doing