We humans need to exercise in order to stay healthy. Exercise protects against disease and early death, and keeps us mobile and able to perform daily tasks.

Walking is an easy, free and enjoyable form of exercise. But is a nice stroll enough to confer the life-saving benefits we know come from exercise?

We posed this question to five specialists in the field.

Four out of five experts said yes; here are their detailed responses.

NO: Jackson Fyfe, sport scientist

Walking is of course better than no exercise at all, but to maximise health benefits, a combination of aerobic-type (running, cycling, swimming) and strength-type exercise (lifting weights or bodyweight exercises) should be performed regularly.

We know being unfit shortens life, and countering the losses of muscle strength/power and bone density as we age can improve our ability to perform daily tasks, while reducing the risk of falls and associated complications.

Walking alone is simply not sufficient for most people, although it may provide a platform to more specific, intense exercise. So moderate- to high-intensity aerobic and strength training should also be incorporated into regular exercise programs.

Of course, this does not mean walking does not have benefits, but there are aspects of the health-promoting effects of exercise that walking alone cannot provide.

YES: Carol Maher, physiotherapist

Physical activity is linked to important and wide-ranging health benefits, such as reduced risk of heart disease, excess weight and obesity, type 2 diabetes, depression and anxiety, osteoporosis and many cancers.

Walking at a moderate pace (5 km/h or 3mph) can largely achieve these benefits, especially if it's done in continuous bouts (say, 10 minutes or more at a time).

Of course, the benefit is even greater if you can get some higher intensity exercise in such as brisk walking or walking up a hill, and throw into the mix some physical activity that challenges your strength and balance.

YES: Julie Netto, occupational therapist

The ConversationWalking brings many benefits. Walking is an activity that can easily be graded up or down to tailor to your personal goals.

You can easily change pace or intensity, or the distance covered. Using Nordic poles (hiking sticks) can also modify the activity so it's more than just a lower limb exercise.

Walking on different gradients and surfaces or carrying a load while walking can add variety and challenge to your workout. In terms of convenience, you can easily walk on a treadmill too.

Walking has been shown to have many physical health benefits and holds promise in alleviating depression. There are also socially supportive aspects to walking, where you could get to know people in your neighbourhood or community, especially if you're a dog owner.

YES: Kevin Netto, biomechanist

If you can walk independently and maintain a speed of 4-6km/h (~3 mph) for half an hour per day, then walking is sufficient exercise.

Walking needs to sustain your interest in the long term. Walking can protect against chronic diseases, and there is less risk of injury compared to other forms of exercise.

It's also free (shoes and active wear aside), and your family, friends and pets can be included. In fact, these have been shown to be a great motivator to continue walking for exercise (the pet and friends, not the active wear).

Walking in challenging environments can be difficult, with pollution and climate being factors that detract from participation.

A treadmill may suffice but who likes walking in one spot! Investigate walking groups that use shopping centres or other indoor areas in the early morning in situations where it's too hot or wet to walk outdoors.

Most importantly, enjoy the experience…exercise can be the best medicine you ever take.

YES: Tim Olds, professor of health sciences

You'll get there by walking, but running will get you there so much faster. The average Australian adult walks recreationally for about 30 minutes a day, and that makes up about 40 percent of all of their physical activity.

We used to walk much more. In a study simulating life in the early Australian colony of Sydney, researchers recorded people walking 4-6 hours each day.

A moderate walk requires about three times your resting metabolic rate, running and sport require much more - typically about seven times. Both walking and vigorous sport will reduce your risk of dying prematurely at any age.

But you have to spend much more time walking: one minute of vigorous sport is worth 3.5 minutes of walking.

To reduce your risk of dying by 20 percent, for example, you would need to walk for 56 minutes a day. You'd get the same benefit by running for 16 minutes.

Alexandra Hansen, Section Editor: Health + Medicine, The Conversation.

This article was originally published by The Conversation. Read the original article.