I'm 6'4 and I weigh 13 and a half stone. I'm 35 years old.

My arms are skinny.

I would dearly love to have big muscly arms and upper body for the first time in my life.

I am prepared to work fucking hard to achieve this goal.

My goal is that instead of people commenting on how small my arms are, they comment on how big they are.

But I need to know what a realistic expectation is. Am I fighting a losing battle due to being an ectomorph body type? Am I too old to go from skinny to ripped in say, 6 months?

My goal is that I double the size of my arms in a year - is this even physically possible for someone with my body type?

And on achieving it - is there some kind of app/program that I can follow to the letter, or would I be better employing a personal trainer?