Hi, ive decided im ready to loose weight and i was very motivated, so i pulled out the treadmill at my house. I got on and i started off just walking. After a few minutes i put the speed up a little so i was walking fast (no incline) and i felt like my heart was gonna come out my chest! Im 5'4 22 years old and weigh 198 pounds (over the past year and a half ive gained 60 pounds) I just feel so unhealthy and being on the treadmill kinda discouraged me. I did a half mile in 20 minutes and it said i only burned 60 calories. My heart was goin so fast, this might sound like a dumb question but can anything bad happen to you from your heart goin so fast like that like have a heart attack from it? Does anyone have any tips how i should start out like how long on what speed? I just dont know what to do i feel so lost.

i'm not a doctor, but i started out at a comfortable pace for me to be able to walk 2 miles, i up the speed every time i feel comfy with my new pace...i'm now at 3.5 on the treadmill but i still only do 2 miles, i just do them faster

dear kklldd, one of the ideas behind treadmill is to increase heart rate so you don't have to worry about your reaction to the workout too much. however, you should start slowly, like Savora suggested and increase the speed slowly when the time comes.
i'm a newbie so i can't link, but try to google treadmill workouts and read some more on it, i hope you will find more info.

First, you should calculate what your target heart rate should be. There are a variety of formulas, but you can go to websites like http://www.changingshape.com/resourc...calculator.asp
and plug the info in and they'll calculate it for you.

Then you can adjust your rate or incline to get to your target heart rate. As time goes on and you become better conditioned, you will have to go faster or have more incline to keep your heart rate in the right zone.