How do I gain weight?!

In general free-weight "compound movements" build the most size and strength. Free-weights build more size and strength than machines because you must use your stabilizer muscles. For example the machine bench-press works your chest, tri's and front delts, but the free-weight bench press also works your back and other parts of your shoulders to help stabilize the bar. "Compound movements" are movements that use more than 1 joint such as bench-press, shoulder press, squat, dead lift, pull-ups and chin-ups. You can go heavier with compound movements than you can with single-joint movements so you can build more size and strength.

For sets and reps you want to generally do 4-5 sets of 8-15 reps per exercise to build muscle. Less than 8 reps make you very strong but you don't get a "pump". The "pump" is from blood filling your muscles because you're doing relatively high reps (8-15). You blood carries nutrients that your muscles need to grow. More than 15 reps does give you a pump but, because the weight is relatively light, your muscles are not torn down because they aren't being challenged. Muscles must be torn down in order to be built back bigger and stronger. This is why 8-15 reps is ideal.

If you're not getting any stronger (for example, your bench-press has been stuck at 180lbs for 10 reps for 2 months or more) then you're probably not building any new muscle either. If this is the case, then it's time to lower the number of reps and increase the weight. Doing a heavier weight for lower reps for a few weeks or months will make you stronger. When you get stronger and then go back up to 10 reps you should be able to do more than before which will break down more muscle and again fill your muscle with blood.

To build muscle mass you should be consuming at least 1-2 grams of protein per pound of body weight. For example, I weigh 180lbs so I must consume 180-360 grams of protein per day. Our bodies don't store protein so we need a constant supply throughout the day. You should be consuming whey protein as soon as you wake up because your body gets no protein while you sleep. You should definitely take 30-40 grams of whey within 30 minutes after your workout and, if you can, maybe 20-30 grams before your workout. And right before you go to sleep you should take 20-40 grams of Casien protein. Casien protein is digested very slowly so it is ideal to take before you sleep.

18 years of weight training

I had a friend like that. You could try working out and gaining the weight in muscle instead, which is what he did. I mean, he's still really thin, but he actually has a really attractive body because of his muscle tone. I wouldn't recommend binging on junk food, as it will also raise your blood pressure and cholesterol levels.

P90x without a doubt, i have been doing it for over 400 days straight now. I have a video on youtube of my results. just take a sec and watch it and i bet you will be motivated after it. i can help guide you through your workouts and answer any questions you have. I'm going to school for kinesiological sciences so this is all about what i am learning.

http://www.youtube.com/watch?v=2TjRka3tG…

You are prob. not going to gain any pounds for a while. I had the same problem growing up, I am also 5'11, 38 years old and now I'm at 175 lbs. I tried so hard to gain a couple but never made it. I can also eat what ever when ever. Sorry!

a lot of proteins and shakes,and eat a lot of food in the morning.

eat nothing but fast food

work on your arms