any exercise that gets your heart rate up including walking will help you lose weight and walking is a very good example as you can do it any where and any time regardless of your fitness level or budget. If you use your arms during your walks you will burn more calories and a good power walk will be a good all over work out and tone many muscle groups. you can add some ankle weights and hold some weights in your hands for extra assistance, or use hills and stairs in your walks ect, there is alot of variation to help keep your walks interesting. there are some dedicated walkers on this site so maybe take a look at them as they are very inspirational with fantastic results HTH