how to gain speed and weight and keeping up

Question
I'm 14 turning 15 in 3 months and I'm only 120 at 5'6 and I'm playing freshman football and I'm afraid that i will get hurt because I'm like the smallest dude who is playing runningback so i want to know how to gain more speed and weight. I also want to know how do i keep up with everybody else because i been going to practice for three weeks and we only have practice two days a week and I'm not keeping up with anybody and i don't even weigh as much as the other guys and they are out running me because I'm not in shape

Answer
Scott,

I have coached many kids in your situation and let me tell you that if you keep working hard in the weight room and on speed work you will get better. I know for a fact that many freshman struggle with this but you just have to let your body grow and keep working out. Desire means so much in football, make it a point to give your best in every drill and coaches will notice. I had a freshman player like you once who was a 4th string o-lineman as a freshman and he worked hard and kept at it and you know what. He ended up being a college QB who set the passing records at his school.

Dont be discouraged! Keep working and as your body goes through adolescence you will see big improvements!

Mark