Walking: What are the health benefits?
Brisk walking is a form of exercise that has a lower risk of injury than many other kinds of exercise. It is easy for many people to do, and people who walk a lot can usually keep doing it late in life. Experts currently believe that people need to get at least 30 minutes of moderate-intensity exercise on most days of the week. However, a large number of people do not get that much exercise. Brisk walking that gets your heart rate up is strenuous enough to be moderate-intensity exercise. So, according to many experts, if you walk at a fairly brisk pace for at least 15 minutes at a time twice a day, then that is enough to get some health benefits.
That is the theory, but what health benefits can you expect if you walk regularly, and how much do you have to walk to get a benefit? Researchers from Ireland and England looked for trials that could answer these questions. They looked for trials which only tested walking, and no other exercise or combination of activities. The trials had to last for at least four weeks, and they had to have measured the impact of walking on risk factors for cardiovascular disease, such as their heart and circulation fitness, blood pressure or body fat distribution.
The people in the trials had to be at least 18 years old. They had to have been quite "sedentary" before the walking trial - which means that they were quite physically inactive before participating in the research. All of these volunteers were then randomly allocated to a group that walked more or a group that continued on with an inactive lifestyle. Random allocation in a trial means that the research volunteers did not choose which group they ended up in. This is important, because it means that the people who were in the "walking group" were not more motivated or already healthier and fitter than the people who did not walk. Randomised controlled trials like this make it possible for researchers to measure any differences that happen just because of a certain intervention, like walking more.
The researchers found 24 trials like this. Although none of them were ideal pieces of research, together they were able to provide information on the health effects of walking. There were over 1,100 people in the trials, with an average age of 52 years. There were many more women than men in the trials, and this might be partly because walking is a particularly popular exercise choice for women. The walking programmes studied in the trials lasted an average of 35 weeks (almost nine months). The average number of days per week that people walked was 4.4 days, which is close to current recommendations for frequency of exercise. The average amount of time they spent walking was 190 minutes - that is over three hours per week. Some people walked just under an hour, while others walked up to four and a half hours a week. Those who spent less time walking, however, walked faster and exerted themselves more.
The researchers concluded that these trials show that walking can lower the risk of cardiovascular disease in people who are currently very inactive. The walking has to be regular, and it has to be "brisk". Brisk walking means that you are walking quickly enough to make your heart and lungs work harder. It is less strenuous than running, and you do not have to be very out of breath, but it should be more than just a normal walk.
Every trial found that people's cardiovascular fitness improved a little if they regularly went on brisk walks over a period of months. This means that their hearts were a little stronger, and they were able to cope with more exercise as well. There was a small beneficial effect on their blood pressure too. The people who spent less time walking, but walked very briskly, experienced the same health benefits as people who spent more time walking, but walked more slowly.
The average weight loss was around 1 kg (or just over 2 pounds), which was 1.4% of their body weight and almost 2% of their body fat. This means that they had a small reduction (just over 1%) in their BMI. The BMI is the body mass index - you can read more about this measure here. Because the trials did not continue for longer, it is not known whether people kept walking regularly and kept losing weight. You can read more about the research on exercise and long-term weight loss here.
The researchers concluded that even the people who walked for less than an extra hour a week experienced health benefits. So if you are a person who is currently very inactive, even one extra hour a week could improve your health. Other research has found several strategies that help people who are living very sedentary lives to walk an extra 30 minutes or an extra hour a week. You can read more about that here. The main thing is to keep it up and get used to more strenuous, brisk walking so that it becomes a natural part of your everyday life.
Author: German Institute for Quality and Efficiency in Health Care (IQWiG)