The report, released by Sports Medicine Australia (SMA) shows that since the 2000 survey fewer people are taking part in organised exercise.
The head of S-M-A, Gary Moorhead says the results are very concerning.
“All of the government efforts to date have been devoted to children, and certainly the figures regarding children's rising obesity rates is very concerning, but it's in fact far, far worse for adults. And it's far, far worse for adults in that middle-aged baby boomer age cohort and they're the ones who are going to be impacting on the health system much sooner than children. And at the moment this is a real blind spot in terms of national planning.”