There are a lot of people out there who feel the only way to loose weight is by running. Running is a very good cardiovascular exercise; it burns calories, raises your heart rate, and gets you moving. But, it is also very hard on your hips and knees and ankles, and there is only so long you can do it for. I have heard many runners say how they feel they have only a certain amount of runs or steps in their knees or hips. This is true. This is because running causes a lot of impact. Each impact, or each time you strike the ground with your foot, you are creating microtraumas. These minor traumas build up over time to cause the joint or joints to break down quicker, thus accelerating the inset of arthritis. As that arthritis, or joint degeneration, progresses over the years, the joint breaks down faster than it would if you were doing some type of low impact exercise. So after a while, it can be weeks or months for some or years to decades for others, the affected joints break down and then will prevent you from running or doing other activities that you may want to do.If you are just starting out exercising, running can be very detremental to your body. If you are slightly over weight, and work in front of a desk, then you will have a lot of problems trying to run. I see a lot of people like this. They will start runnning and within a month to 2 months of beginning their new running routine, they will injure themselves and will not be able to continue with the running. This is because the muscles in the hips and knees and legs are already very tight from sitting all day. These tight muscles will cause the joints to be out of balance or alignment. This muscluar imbalance coupled with excess weight will drastically increase the load on the joints and cause them to get irritated or injured very easily.Someone starting out exercising would be much better off just walking for a half an hour 3 days a week to start out. You won’t burn as many calories as you would from running, but you will be able to stick with the walking (or some other low impact type of cardiovascular exercise such as: elliptical machine, stationary bike, rowing machine, swimming, etc) for a much longer time and do it more consistently. Doing the low impact exercise more consistently will allow you to burn more calories overall and therefore stick with the exercise longer. The overall result will be that the person will be in better shape and loose more weight overall, than if the person were to start out trying to run.Now that is not to say that no one should run. Running is a good exercise, but for those of us who are in decent shape and are not overweight. I would not recommend running if you weight over 160 lbs. The excess weight just puts too much stress on your joints and will cause them to break down quickly and will cause an increased incidence and early onset of, osteo-arthritis.