At least you understand that you have to eat to gain weight.
To gain weight you need a caloric surplus in your body. 3500 calories = 1lb. Now, you can eat a lot and just put on weight, or you can do mass gaining type workouts (ie. Bodybuilding style) and therefore, in essence, “direct” the protein into your muscles. This is the way to put on mass that looks good.
Since you said you were skinny and you eat a lot, you will probably never be huge.
We seem to burn all of it very fast. both hyper-active,
There is a saying in bodybuilding “Never run when you can walk, never walk when you can stand, never stand when you can sit, never sit when you can lie down, and if you can lie down, you might as well take a nap.” The meaning behind this is that in order for bodybuilders to get as big as possible, they have to burn the least amount of calories possible. As a side note, professional bodybuilders are some of the most unhealthy people in the world… many of them cannot even walk across stage without becoming out of breath. However, their goal is not to be healthy or good athletes, their goal is to become as big as their genes will allow.
Now, this is not to say you can’t add some mass an still be an excellent athlete. But, by keeping up your aerobic activity, you will by definition be burning more calories than if you didn’t. So to compensate for this you will probably have to eat more.
Putting on size is a gradual process. Do not jump in to eating thousands of calories a day. Gradually build up. Make sure you eat at least one gram of protein per pound of bodyweight once you start your mass building routine. Also, be prepared to be sore following your workouts and know that this will have an effect on your other sports as well.
Most importantly, I know at 17 it would be cool to be huge, but you may not be done growing yet so don’t rush things. I know that’s not what you want to hear, but as a 21 year old who was 145lbs at 5’9" in highschool, I know what you are going through.
One more thing, I assume you are an ectomorph (naturally skinny, low bodyfat, hard to put on muscle or fat). If this is the case, any muscle you put on will automatically be ripped because your bodyfat is naturally low. If you don’t have one already, it will be fairly easy for you to develop a six-pack.
Good luck,
IronFist