It's cheap, you can do it anywhere, and you already know how to do it.
Whether you are working off a belly acquired over Christmas, or looking for a regular way to improve your health, putting one leg in front of the other is the way forward.
Britain's National Health Service (NHS) advises that walking 10 000 steps a day, or 8km, can give you a healthy heart, reduce body fat and improve cardiovascular fitness.
It can help you to cope with stress, and may even reduce the risk of Alzheimer's.
The NHS also claims that anyone can turn back the clock three years by getting even a small amount of exercise, such as taking the stairs instead of the lift.
Walking can also improve our bone density, because it is a weight-bearing activity.
And as it is low impact, it does not place unnecessary strain on the joints, as running can.
The best way to do exercise walking is to team up with a friend.
"There's nothing like walking with someone else," says Martin Christie, a London-based personal trainer who specialises in the pole-based Nordic walking.
"All the studies show that if you go out with someone else, you are much more likely to stick to it."
You can build walking into your daily routine - by incorporating a longer walk into your daily commute, for example.
Experts recommend that you stop driving to the local shops, or get off the bus one stop early and walk the rest of the way.
Equally, taking a walk in your lunch hour, or after a meal, cuts the amount of fat your body stores.
But if you want to step it up a level, there are now a number of types of exercise walking "techniques" that are a bit more demanding and offer greater benefits.
Nordic walking
Nordic walking is essentially propelling yourself along with the help of hand-held poles angled back at about 45 degrees.
The technique allows you move faster by taking the load away from the knees and hips and bringing the upper body into play, so making the exercise more comfortable.
"Because we are using our body above the waist, it works the back, chest, arms and stomach," Christie explains.
"And, as it uses more muscles, it burns 20 percent more kilojoules, which increases to 46 percent with good technique."
The important thing is to move the poles in a natural movement, angling them back, and with the arms relatively straight.
Then, swing the arms from the shoulders rather than bending the elbows.
Crucially, make sure that you move your left arm forward along with the right leg, and vice-versa - and then work yourself as hard as you can.
(See www.nordicwalking.co.uk.)
Pacer poling
Pacer poling makes use of similar techniques to Nordic walking, but it employs a different kind of pole.
Christie explains that the ergonomically designed handle makes the extension of your arm and the handling of the pole much easier, and allows you to propel yourself more efficiently.
Essentially, what you are getting is more power for less effort, and this puts less strain on your body.
"Lots of people, especially the elderly, find the handle more comfortable," Christie says.
"There's no strap (which Nordic poles have), so you can pick it up and go straight away.
As with Nordic walking, in a single session you should be able to learn all the basics."
(See www.pacerpole.com.)
Power walking
Power walking is simply walking at a speed closer to the upper end of the natural speed range for the walking gait.
At such speeds, jogging and power walking burn roughly the same amount of energy.
Many people opt for speed walking rather than jogging, as the walking gait creates less impact on the joints.
To qualify as power walking, as opposed to jogging or running, at least one foot must be in contact with the ground at all times.
"The great thing about this is that you don't need any walking equipment," Christie says.
"You just get a pair of trainers and away you go. It's a more vigorous use of your upper body and so will increase kilojoule consumption."
(See www.powerwalkersworld.com.)
MBT walking
MBT (Masai Barefoot Technology) shoes, which have been dubbed "anti-shoes", are popular with celebrities and those who can afford the cost of up to R2 100 a pair.
The curved soles of the shoes, in effect, transform flat, hard surfaces into uneven, soft terrain.
While the top of the trainer looks like a regular running shoe, the sole is rounded from the middle of the heel to the ball of the foot, to create an effect almost of rocking forwards and backwards on your feet.
The shoes' manufacturers, the Swiss firm Masai, claim the shoes help posture and reduce foot pain.
Initially they feel strange to wear, and are hard to adapt to.
As they work best while walking on flat surfaces, they are useful for a quick spin during a lunch break, as opposed to walking across a park.
MBTs may not be for everyone, and some specialists question their effectiveness.
"The claims as to assisting posture, and (helping with) back, hip and knee problems are not supported by evidence, or any good rational explanation," says Dr David Johnson, consultant orthopaedic surgeon at St Mary's Hospital in Bristol.
(See the MBT section on the King's Road Sporting Club website at www.krsc.co.uk.) - The Independent