Health experts have come to conclusion that low-intensity walking many people use as a form of exercise may not have significant health benefits compared to moderately intense workouts and they advise picking up the pace a little bit, so that the whole walking wouldn’t be in vain.
It is not in the number of steps you take, experts say, but in the effort you make to take these steps. In order to benefit from your walking, you should walk faster.

Higher intensity activities have positive effects on oxygen consumption, body fat control, lipid/glucose metabolism, etc

The reason I mention the number of steps is because of a popular 10,000-step program. The effects of this program were compared with a traditional aerobic fitness program (moderate intensity on a treadmill or stationary bicycle) and it was found that the traditional fitness program improved aerobic fitness and reduced blood pressure more than the 10,000-step walking program.

The researchers came to conclusion that the 10,000 step program could be used as a starting point and that higher intensity activities should be introduced some time after.