Walking is one of the simplest forms of exercise. It’s also gentle on your joints, low impact, and free! Walking for just 30 minutes’ burns between 100 - 200 calories, depending on how fast you walk and whether you are walking up a slope.. Unless you are using a treadmill, walking does not require any investment. Another plus point is that unlike most exercises, walking does not have to be a boring and repetitive activity - you can simply choose a new walking route or get a friend to come along with you. However, as with any exercise, it's important to have the right technique so that you can get the most out of it.