What's the minimum amount of exercise you need to stay healthy?

While some of us are setting big exercise goals at the start of the year, like preparing for a marathon, others are simply aiming to put in the bare minimum needed to stay fit and healthy.

If your fitness goals for the year are simply to ward off ill health and maintain your day-to-day fitness, you might be wondering: How much exercise do you really need to do? And does walking around the block count?

We asked four experts, and we were pleased to hear it's possible to get results without slogging away for hours each day.

Get to know the guidelines

Australia's national exercise guidelines (yes, the government has done the work for us) suggest accumulating 150 to 300 minutes of "moderate intensity" physical activity, or 75 to 150 minutes of "vigorous intensity" physical activity, each week (or an equivalent combination of both).

That's an absolute minimum of two and a half hours of moderate intensity activity, or one and a half hours of high-intensity activity, per week to stay healthy. (Ideally, you'd be doing double that.)

The guidelines also recommend doing muscle-strengthening activities at least two days each week, and minimising the amount of time spent sitting.

These guidelines apply to adults aged 18-64; there are different guidelines for other age groups.

Make walking and other incidental activities count

If you've been avoiding exercise because you hate sports, the good news is: there's a form of activity out there that'll suit you.

Many can be incorporated into your daily routine — no gym membership required.

Riding a bike, hiking with friends, or using an elliptical trainer while watching TV are all options. Just make sure you're doing them at a brisk enough pace that requires some effort.

Depending on your distance from the office, "walking to and from work is a great thing to do because it builds it into your day and it just becomes routine," says Professor Wendy Brown from the University of Queensland's School of Human Movement Studies and lead author on the report that led to the current guidelines.

If you already have a pedometer and aim for 10,000 steps per day, you're probably already hitting the minimum exercise targets, says Professor Timothy Olds, from the Health Sciences School of the University of South Australia.

"In 30 minutes, you'd probably do 3,000 steps, and of the 10,000 steps, it may be that 4,000 of those are what we call background steps, like steps you take around the house," he says.

Timothy Fairchild, an accredited exercise physiologist and Associate Dean (Research) at Murdoch University's School of Psychology and Exercise Science, agrees.

"If someone hits 10,000 steps a day, then I'd be guessing that they'd be hitting their minimum number of physical activity targets," Dr Fairchild says.

Smaller chunks of exercise count

If the idea of a 60-minute slog at the gym intimidates you, you'll be pleased to hear adults can meet the minimum physical activity requirements by adding short bursts of exercise together.

Each burst should be at least 10 minutes long (a brisk walk to the bathroom won't do the trick. Sorry!).

Bonus tip: If you only have a short amount of time to exercise, you'll get more value out of your workout if you make your exercise vigorous.

"That's why there's high-intensity interval training (HIIT)."

Build in some muscle-strengthening exercise

You'll need to complete two sessions of muscle-strengthening activity each week to meet the national minimum requirements.

"You need to be doing strength training, whether that's lifting weights or doing body weight exercises. So you need to be putting your muscles under load, and you need to be doing it regularly," says Sydney-based personal trainer Cassie White.

You're unlikely to get enough of this kind of workout from incidental activity, unless you work as a labourer or are an extremely keen gardener (that would involve "digging and putting things in a wheelbarrow and lifting pots — not going out with a pair of secateurs and clipping the roses," says Dr Brown.)

That means you'll probably need to actively create a muscle-strengthening routine.

If lifting weights isn't for you, consider finding a workout online, says Ms White. She recommends a routine involving body weight exercises such as squats, lunges, push ups, planks and hip extensions.

"All you need to do is google 'body weight exercises'. And if you're open to picking up some resistance bands, then you've opened up another world of exercises you can do at home."

Pilates and yoga also count, whether you attend a class or find one you like online.

While the guidelines don't say exactly how long these muscle-strengthening workouts should last, Dr Brown suggests a 15 to 20-minute routine.

"If you did that really religiously twice a week, it would prevent your muscles from disappearing by the time you reach 60," she says.

Spread your activity throughout the week

Being active on most, and preferably all, days of the week is best, the guidelines say.

But if you're only doing two or three sessions, it's best to spread them throughout the week.

"The one recommendation we would say is you shouldn't have any more than one day back-to-back where you haven't performed exercise," says Dr Fairchild.

So if you exercise on a Monday, you can skip Tuesday, but you should exercise on Wednesday.

Sit less and move more

The guidelines recommend minimising the amount of time we spend sedentary (sitting or lying down for long periods), and breaking up long periods of sitting, to help guard against a host of health issues including weight gain, type 2 diabetes and heart disease.

Using a standing desk, walking to get your lunch, or incorporating walking meetings into your day can all help.

Limiting your screen time at home can also encourage movement: How about taking your dog for a brisk walk instead of watching that second episode?

Take it seriously

Ultimately, these exercise goals really are achievable — but you have to take the time to review how much activity you're really getting, and schedule it in if needed, the experts tell ABC Everyday.

"We have to move more. And we're just not doing it," Dr Brown says.

Professor Olds says the benefits of exercise extend far beyond weight loss and aesthetics.

"Exercise affects so many different health aspects: physical health, mental health, everything from diabetes to depression, from asthma to eczema. It's extraordinarily powerful, the effect of exercise," he says.

"We've had a look at the effect of sitting, the effect of sleep, the effect of physical activity — and every time, for every disease, for quality of life, for academic performance, for physical health, for mental health, depression, stress, anxiety, it's physical activity.