Walking: good exercise or not?

There is nothing magic about either walking or running. They are just two exercise activities.

When it comes to cardio, WHAT you do is not as important as HOW you do it. You just have to understand the nature of each activity and match your workouts to your goals.

First: there is a difference between exercising for FITNESS and being active for WEIGHT LOSS. Exercising to improve fitness requires that you work out at a certain intensity threshold, and at a minimum duration and frequency. Being active for weight loss means......just moving around more.

Ideally, you would like to work on both at the same time, and realized the benefits of both fitness improvement and weight loss. Sometimes, there are physical challenges or other limitations that make that more difficult.

So, let's get back to walking and running. Both burn calories. Walking is a less intense activity. It is also low-impact and thus a very safe and comfortable way to start working out. Even at what most people would consider "brisk" walking speeds (4.0-4.2 mph), the amount of calories you burn will be about 4 times that at rest. Depending on your fitness level, that might be intense enough, or it might not.

Running, even at slow speeds, is a higher-intensity exercise. Running is defined as a gait in which, at some point, both feet are off the ground at the same time--speed is irrelevant. Even at slower running speeds, the intensity is notably higher than walking. For example running at a 12 min/mile pace (5 mph) will burn calories at about 7 times that at rest, running at 6 mph 10 times, etc.

However, not everyone can run. The higher calorie burn results from a higher intensity of effort, and some people, esp beginners, do not have the fitness capacity to sustain that effort. That's important to understand: Not everyone can run--no matter what the supposed "benefits" might be. Running is also an exponentially higher-impact activity than walking, so the injury rates are significantly higher as well.

Some people might be stuck in the middle--they might have the fitness capacity to run, but they either have physical limitations that prevent running or just don't care for the activity. At that point, they have to make some choices: accept a lesser degree of fitness improvement, try some modifications to improve the intensity of walking effort, try a walk/jog interval program that increases their fitness level, or choose another exercise modality that has a more gradual "scale" of workload increases.

But if you are primarily interested in just burning calories, walking can help to accomplish that task. It's just going to take a longer workout session than if you were running. You can increase the intensity of walking by walking up hills (or incline walking on a treadmill) or using a more vigorous arm swing.

To me, the biggest downside to walking is that it is easy to lose focus and not push yourself as hard. Since walking is such a familiar activity, it is easy to fall into a habit of walking at a normal "pedestrian" pace. You just have to make sure you see your walking sessions as "workouts", pushing the pace and working those arms to get the most benefit.

Reading the other comments should give you an idea of the volume of exercise that will provide the best results. As long as you understand how walking works and you structure your program accordingly, walking can be very effective for weight loss.