By Cassie White

Taking 10,000 steps every day has been one of the biggest public health messages this decade.

Clocking the Big 10 is said to be the key to reducing our risk of serious illnesses associated with inactivity, such as diabetes, heart disease and cancer.

That message has been heard loud and clear: everyone from kids to corporate high-flyers has a fitness device strapped to their wrist, quantifying every step.

Here’s what you might not know: the 10,000 steps rule didn’t originate from much scientific evidence.

In fact, “10,000 steps” is the translation of a Japanese word, “manpo-kei”, which was the name of a pedometer.

In the 1960s, a researcher in Japan discovered that most people took less than 4,000 steps per day. He found that increasing those steps to 10,000 could improve overall health.

It was a nice, round number; it gained momentum and before long 10,000 steps became a worldwide phenomenon.

The issue is that 10,000 steps is often mistaken as a magic number — the key to staving off diseased caused by inactivity — when, in actual fact, it’s a basic guideline.

Since the 1960s, studies have primarily found that taking 10,000 steps a day is definitely better for your health than doing nothing at all. Big surprise.

But, is it enough?

Probably not, according to a new study in the International Journal of Obesity, which tracked Scotland’s postal workers. Researchers compared the health of postal workers who delivered mail on foot with those who sat at a desk.

They found that 15,000 steps appeared to be the actual magic number, since those posties had normal waistlines and no increased risk of diseases associated with being sedentary.

The researchers also noted that for every hour spent sitting down past five hours, workers had a 0.2 per cent increased risk of heart disease.

Sedentary to superhuman

If you lead a sedentary lifestyle, where you commute to work, sit at a desk all day, then zonk out on the couch at night, chances are you’ve probably been struggling to reach 10,000 steps.

So what does this new development mean for you?

It means two things:

1). You’re not alone — less than one in five Australians are reaching anywhere near 10,000.

2). You’re not moving nearly enough to be considered healthy or reduce your risk of disease.

And because most of us can’t make it to 10,000 steps, that will remain our goal, explains Associate Professor Emmanuel Stamatakis, from The University of Sydney’s School of Public Health.

“We have to be realistic about how difficult it is for people to change their lifestyles,” he says.

In other words, why strive for 15 when 10 is still so far out of our reach?

Exercise becomes much more important once we hit our mid-forties, because it’s when our risk of cardiovascular disease and diabetes significantly increases, Professor Stamatakis explains.

Unfortunately, it’s this age group who are the most sedentary.

“For middle-aged people who haven’t exercised since school — and that’s not an extreme scenario, by the way — even 3,000-5,000 steps is good enough,” Professor Stamatakis says.

“What matters is being able to sustain it long-term, then build on that towards 10,000 steps and try to increase the intensity.”

Intensity over distance

While reaching a target amount of steps might seem straightforward, there’s a big difference between doing 10,000 steps dawdling to the photocopier, and working up a sweat.

Australia’s physical activity guidelines recommend:
Accumulate 2.5-5 hours of moderate-intensity exercise, or 1.25-2.5 hours of vigorous-intensity exercise per week, or a combination of both;
Break up extended periods of sitting;
Do muscle strengthening activities (e.g. go to the gym, or do bodyweight exercises) at least two days per week.

“To be considered moderate intensity, in general most adults need to take 100 or more steps per minute,” Professor Stamatakis explains.

Anything slower is incidental exercise and while it’s still valuable, you’d need to walk several hours a day to experience health benefits.

So, rather than wandering around aimlessly until your activity tracker strikes 10,000 (incidental exercise), you’d be much better off taking fewer steps with more effort, making a large chunk of them moderate-intensity.

“Essentially, you could take 7,500 steps per day, assuming that 3,000 of those are at least 100 steps per minute,” Professor Stamatakis recommends.

Or, if you have the time and want to challenge yourself: 10,000 steps at 100 steps per minute = one hour and 40 minutes of moderate-intensity walking.

Do it in two blocks and use it as your commute to/from work, or grab a walking buddy and get it done in one big hit.

Don’t get complacent

However, if you’re part of the population that consistently reaches 10,000 steps per day, it’s time to up your game.

When it comes to exercise, the law of diminishing returns applies: you see the biggest improvements when going from nothing to something. Then, the more you do, the smaller those improvements become.

Which means that just aiming for 15,000 steps isn’t going to cut the mustard, especially if you want to lose weight and get fit.

And besides, who other than a Scottish postie has the time to do that?

So, schedule in weekly exercise sessions, such as strength training and high-intensity cardio.

Continually increase the intensity at which you exercise, eat healthily — and do it all consistently. Plus, take 10,000 steps a day.

This is why the physical activity guidelines speak to intensity and time accumulated, rather than steps.

Science has proven time and again that a combination of moderate- and high-intensity exercise, strength training, reduced sitting time and, yes, incidental exercise will have the greatest impact on our health.

You’ll lose fat and get stronger, which is often all we really worry about.

But you’ll also spark many crucial physiological and metabolic processes that don’t count for much when it comes to vanity, but mean everything for living a long and healthy life.

They are:
Increased bone density,
Lower blood pressure and LDL cholesterol;
Increased cardiovascular and overall fitness;
Better mood and reduced risk of depression;
More energy;
Much lower risk of metabolic diseases, eg, diabetes
Much lower risk of cancer and all-cause mortality

When it’s written down, doesn’t the list of exercise pros far, far outweigh the cons?

If you’re not moving enough, start now and start small. Remember, something is better than nothing, so build gradually and make it consistent.

And if you’re consistently clocking 10,000 don’t get complacent — moving even more can only be a good thing, for vanity and living well.

Cassie White is a Sydney-based personal trainer, yoga coach and health journalist.

This post originally appeared on ABC News.