Megan Teychenne and Clint Miller: Staying healthy a walk in the park

Walking has been shown to reduce the risk of a range of health problems. Photo / Mark McKeown

Walking is free, easy and it can be done anywhere Megan Teychenne and Clint Miller

There are plenty of reasons to walk, we've been doing it since the dawn of time.
We all know we need to exercise to stay fit and strong, stave off disease and maintain a healthy weight. Walking is the most popular physical activity undertaken by Australian adults. It's free, easy, and can be done almost anywhere.

Walking leads to a remarkable reduction in the risk of heart disease, type 2 diabetes, some cancers, arthritis, depression, anxiety and insomnia, and premature death from all causes.

The health benefits of walking stem from the changes that occur in our body systems as a result of exercising. For some of these health conditions, fitness has been shown to be a particularly important factor for prevention.

The term fitness is quite often used to describe aerobic fitness, but having a high level of fitness actually refers to all components of health-related physical fitness which includes muscular strength and endurance, flexibility, body composition, and of course aerobic (or heart) fitness. So is walking enough in terms of the exercise we need?

Aerobic fitness
An analysis of studies on walking showed it improves aerobic fitness - which is technically the ability of the heart to get oxygen to our muscles and how effectively our muscles use that oxygen. But to be effective, walking needs to be of at least moderate intensity, which means an intensity where you're able to notice your breathing but can carry on a conversation without noticeable pauses between words. For many, this is a brisk walk.

Greater improvements in aerobic fitness can be achieved when walking at a vigorous intensity, where you can converse with a friend, but it will be interrupted with noticeable pauses between words to take a breath.

The good news is that you don't need to walk at a vigorous intensity for health or aerobic fitness benefits. Walking at a moderate intensity will increase your aerobic fitness and, more importantly, your endurance (the ability to carry out activities for longer with less fatigue). This is because it allows your body to burn fat more efficiently, improves delivery and use of oxygen in the muscles, and improves mitochondrial density and efficiency (these are producers of energy in our body), all leading to greater capacity to undertake tasks with less fatigue.

Walking briskly for 30 minutes five days per week can improve aerobic fitness. Each walking bout doesn't need to be long though; walking for ten minutes three times per day is as beneficial as walking for 30 minutes in one go.

Strength
Walking is not a strength-based exercise, but if you haven't exercised in a while, you'll notice gains in leg strength as a result of regular walking. Although benefits in strength are modest, research shows walking 30 minutes five days per week at a moderate intensity helps to prevent sarcopenia (age-related loss in muscle size and strength).

You can increase the demand on your lower body muscles, bones and tendons to keep them strong by introducing hills, choosing to take the stairs, walking on undulating terrain, or even carrying a comfortable backpack. But maximum strength gains will come from introducing some form of body-weight or gym-based resistance training exercise.

Flexibility
Walking does not lead to significant gains in joint flexibility, but walking regularly does have positive effects on your joints. Weight-bearing exercise, including walking, increases lubrication and delivery of nutrition to your joints.

Research shows that walking regularly reduces pain and disability for adults suffering from knee arthritis; and moderate intensity exercise can protect against the development of joint degeneration.

Body weight
Moderate intensity walking can prevent weight gain and assist in maintaining a healthy weight in as little as 150 minutes per week. The American College of Sports Medicine recommends 250 minutes or more exercise to lose a modest amount of weight, but the more you do, the more you'll lose.

Unfortunately, it's a myth that calories in equals calories out. Don't expect a 500 calorie walk to offset the negative metabolic effect of a 500 calorie treat. Fortunately, regular exercise and being physically fit will reduce your risk of heart disease and early death irrespective of your weight loss success.

There are plenty of reasons to walk, we've been doing it since the dawn of time, well before the first gym opened. Walking is an organic, natural, gluten free, fat free, toxin free, meditative experience that delivers far more health benefits than most other decisions you'll make today.

Megan Teychenne is Senior Lecturer, Physical Activity and Health, Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University
Clint Miller is a Lecturer, Clinical Exercise Physiology, School of Exercise and Nutrition Sciences, Deakin University.