Weight Training

Hi, I am 19 years old and weigh 100 pounds, almost impossible to gain weight...
so I recently started trying to build muscle in march and bought dumbbells, right now I am lifting 15 lbs about 30 reps, wait 3 min, 25 reps, wait 3 min, 20 reps. I usually do this for like 30 min at the most in a day. I am wondering if this will ever give me results because so far I don't see any. Is there a wrong way to lift? Usually I keep top of my arm straight down and lift only forearm up all the way.
Oh, when I try to switch to 20 pound dumbbells, it is too much for my wrists. Even though I keep them stiff, they still sprain. My arms are strong enough but wrists are way too skinny.

Thanks.

[marissposa]

What is your diet like?  You'll need a lot of protein, calcium and an above average calorie intake.  Give us an idea of what you eat in an average day.
Also to bulk up you want to totally exhaust the muscle.  Lift as much weight as you can (ALWAYS tighten your abs when lifting and engage your pelvic floor -the muscles you use to stop the peeing-  to protect your low back).  You can do fewer reps, but with more weight and stop only when you can't take anymore.  Rest about 30 sec and do a few more-- even just 2 at maximum weight.  Rest than do even just one more.  By now (if you are using enough weight)  your muscle should be screaming.  Eat protein within 1/2 hour of lifting.  Drink a lot of water to flush the lactic acid out of the muscle.  Then rest the next day, or work a different muscle group.  Always let the muscles worked have a day to recover, or you'll just breakdown what you build up.
Good luck

[ktm125]

I usually eat stuff like hot dogs, hot pockets, canned food, ramen noodles.
I never knew about tightening abs and stuff, and I never knew to work out every other day. Glad you said that, that would actually be easier than every day lol
thanks a lot :)

[marissposa]

you're welcome.   I would get more protein than that  add some sliced boiled eggs or tofu to your ramen, eat canned beans, etc.  I heard football payers drink chocolate milk to bulk up.  good luck and have fun lifting :)