I jog on the treadmill off and on for 80 min is that bad on account im only 14?

My dad goes to the gym for aprox 2 hours. So i go on the treadmill for more than half the time. Is that bad for someone my age to do almost everyday. I don't want to faint or anythimg and i drink lots of water. I know its good to excercise but is that to much. :)