Walk or Run? Energy Use Is What Counts

Walking and running are equally good for your heart, a new study finds. But if you're a walker, you have to do more of it to get the same benefit as a runner. So concludes the study of 33,000 runners and 16,000 walkers. They were part of two long-running health studies of people devoted to these pursuits. Researchers looked at how many people developed high blood pressure, high cholesterol, diabetes or heart disease in the next 6 years. Both runners and walkers were less likely to develop these conditions if they used more energy in their daily exercise. For each standard unit of energy used, risk reduction was similar for runners and walkers. But overall the runners were healthier. That's because, on average, they used more than twice as much energy as walkers did. Researchers said they probably used more energy because they could exercise in less time. Runners were about 37% less likely to develop high blood pressure or high cholesterol than the walkers. They were 71% less likely to develop diabetes. The journal Arteriosclerosis, Thrombosis and Vascular Biology published the study. MedPage Today wrote about it April 4.

By Robert H. Shmerling, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

When it comes to exercise, my wife likes to walk. I like to run. So we keep having a friendly argument about which is better.

She does have a point. There are many reasons to recommend walking:

• It's generally safer than running. Injuries tend to be less frequent and less significant for walkers than runners.
• It's generally easier to find a place to walk than to run. For example, a busy sidewalk or a shopping mall may be fine for walking but not so good for running.
• Walking puts less stress on the hips, knees and feet.

On the other hand, running can:

• Provide a "runner's high" (and you don't hear much about a "walker's high")
• Provide a more intense workout, which is particularly important if you have limited time to exercise
• Allow you to cover more ground in a shorter time, which helps if you are doing errands or exploring your surroundings while exercising

But does running help the heart more than walking? A new study compares the benefits of walking and running among nearly 16,000 walkers and more than 33,000 runners over 6 years. The researchers collected data on new diagnoses of heart disease and factors that increase the risk of heart disease (such as high blood pressure and diabetes).

They compared the benefits of walking or running by analyzing similar amounts of exertion. For example, walking at 3 miles per hour for 60 minutes and jogging 5 miles per hour for 25 minutes burn similar amounts of energy.

The findings were striking. Walking and running provided similar benefits when energy use was the same. The more energy spent at walking or running, the greater the benefits.

Do these results suggest that walking is just as good for you as running, or even better? That's hard to say. The authors compared similar "doses" of exercise. But if you looked at how runners and walkers actually exercised, runners spent more than twice as much energy as walkers. The runners simply got more exercise. So they had greater reductions in risks of high blood pressure, high cholesterol and diabetes.

The key question is whether walkers will spend the extra time it takes to burn the same energy as runners. If they do, this study suggests the benefits will be similar. And that's good news for non-runners!

What Changes Can I Make Now?

If you're not physically active, the most important change to make is to get moving. The first step is to commit to making physical activity a routine part of your life. Then consider making these changes:

• Embrace "non-exercise" exercise. For example, take the stairs instead of the elevator. In the parking lot, choose the spot farthest from where you are going.
• Find exercises you enjoy. If you don't like running, try something else (such as walking!). You're more likely to stick with something you like.
• Start slow and gradually increase how long and how intensely you exercise. A good rule of thumb is to increase the time or intensity (but not both at the same time) by no more than 10% per week.
• Make exercise a social event. Having an exercise partner (or a few) can make exercise much more enjoyable.
• Cross-train. If you vary your activities, you may be less likely to become bored or injured.

As this latest research shows, walking may be an excellent exercise whose benefits may have been underestimated in the past. Aim for at least 45 to 60 minutes of brisk walking most days of the week.

What Can I Expect Looking to the Future?

You can expect to hear much more about the importance of physical activity and studies that look at its effect on health and disease. This latest research compared the effects of running and walking on heart disease and related risk factors. But there are many other benefits of exercise. Reduced risks of some cancers, osteoporosis and depression are just a few.

In the future, public health programs will continue to encourage physical activity in a major way.

As for my wife, she's right, as usual. Walking is better -- unless you prefer running.