[header] How to walk for exercise indoors [title] Start out easy. [step] If you are new to walking for exercise-especially if you are overweight or lead a sedentary lifestyle-it's important not to push yourself too hard when you first start walking indoors for exercise. For instance, walk only a mile or two (two to four kilometers). 
This way, you'll be able to build endurance and speed over time. [substeps] Before you begin walking, consult a doctor.