Perhaps the single biggest health message we hear these days is we should exercise more.
For many people it comes down to a decision between walking and jogging.
So which of those two will help you lose the most weight? Which is better for your general health? What are the dangers?
Reporter Brooke Hanson puts her best foot forward to find the pros and cons of walking versus jogging.
At the University of Melbourne's department of physiology, Dr Gordon Lynch studies the effect of exercise on our bodies.
"Running and walking are both fantastic exercises and both are going to be great for our health," says Dr Lynch.
But which is better?
Gordon's got a test in mind for Brooke and her student mate Andrew who admits he's not quite at peak fitness.
"I'm fit for what I do, I suppose, [but] probably not as fit as I should be."
So it's a simple treadmill test. Brooke and Andrew's heart rates will be measured as will their oxygen use and calories burned.
Brooke: Just walking, Brooke's heart rate is 79 beats a minute. By the time she's hit a good running pace of about 12km/h, her heart rate has climbed to 159 beats per minute. That's a solid work out.
Andrew: Given Andrew's lower fitness level, he's kept to a solid walk, and his results will be used as a comparison to running. Andrew's walking heart rate is already one hundred and eight he's struggling.
Andrew: "I'm feeling much more unfit than I did before, after looking at the numbers ... "
So first up, the test has shown that we all need to find our own exercise level, but what else has it told us about running versus walking?
Lets start with weight loss:
That boils down to who burns more calories. "The food we eat is energy in and how we exercise, how we burn energy, is energy out, so the balance between energy in and energy out is whether we increase or decrease weight," explains Dr Lynch.
By running, Brooke was burning energy at twice the rate of Andrew walking 10 calories a minute to his five.
So in terms of weight loss, running wins hands down.
In general, you have to walk nearly an hour, to get a similar weight-loss benefit to a half hour run.
"I started running when I was ten-years-old ... I was a skinny little kid who loved to run, it was only a matter of time before I started running marathons. I really love being able to just put on my shoes of a morning and then just go for a run, however far I want to go," says Commonwealth Games gold medallist, Kerryn McCann.
We know walking delivers similar benefits, but for the sake of the argument, which will give you more?
"Intensity is the key here," says Dr Lynch. "We need to make the exercise a little more intense if we're going to get the benefits for our health."
Because running is more intense, the general health benefits are higher.
Within reason, more pain is more gain … Brooke's mate Andrew's got some work to do.
"I need to start walking up hills, not down them," says Andrew.
Walker or runner, you'll get most benefit if you aim for thirty to sixty minutes a day. It doesn't have to be all at once three or four fifteen minute blocks through the day is just as good.
Now there's one last area in this argument, where walking has the clear edge: injury.
"There's going to be much less injury associated with a low impact exercise such as walking, and that's why we can advocate walking for a lot of people, especially if they're overweight or have a cardiovascular condition, they're still going to get a lot of benefits from a brisk walk," says Dr Lynch.
The impact of running on your joints can be more than three times your body weight, every step is triple the impact of walking. You have to train your body to get used to the jarring. Ultimately that's the message, for walking or running find your level, then build up slowly and the benefits will come, in weight loss and general health.
"Set your goals, set them small and work towards achieving those goals and getting a little bit further every week," says Kerryn.
So there you have it ... the old saying "you've got to walk before you run" is true. There are proven health benefits for both forms of exercise, but it's a matter of working out what's best for you.
Remember, it's always a good idea to consult your doctor before you start any new exercise regime. But once you do, chances are you'll feel the benefits for years to come.