make me burn lots of calories and fat? I am 16, female, and weigh 133 5'7 and a half. My weight might seem fine but l do have fat on my stomach and thighs that l could definately lose. l will alternate between running and walking up and down the stairs. How much calories and fat can l lose running up and down the stairs for 30 minutes make me lose, taking a break in the middle?
l am afraid that l might hurt my knees though

It would work if you can keep going without stopping. Going upstairs at a fast pace is very hard. But, with time you will get better.

running up and down stairs is quite strenuous on the knee joints so maybe start with simple less vigourous excersize such as walking, core strength excersizes, squats ect then try jogging and more vigourous activities. The weight will begin to go if you maintain a healthy diet all throughout your excersize.

Stair running is an excellent way to burn calories & tone legs. Because ur legs r working through a longer range of motion by stepping up stairs, more of ur leg mscles r being used & u will get a noticeable tone. In order to minimize any damage to ur knees, l want u to focus on being as smoothe as possible. When u r walking down the stairs do not thud thud thud, try to be quiet & smoothe. This will protect ur knees & will help u burn even more calories. In 30 minutes of this, at a decent pace, u should burn about 250 calories. If u do this 4-5x a week u will lose at least a pound a month without doing anything else as far as excercise or diet. Combine it with a more healthy diet & some simple ab or leg exercises & u will lose about a pound a week.